The Vatreni head into their opener having won just one of their last seven World Cup fixtures, but will be hoping to make use of Argentina and Iceland's 1-1 draw earlier this afternoon.
Nigeria find themselves in a similar run of tepid World Cup form, despite reaching the last 16 in Brazil four years ago.
Follow all of the live action with our minute-by-minute updates below.
CROATIA: Subasic; Vrsaljko, Strinic, Lovren, Vida; Rakitic, Modric, Perisic; Kramaric, Mandzukic, Rebic
CROATIA SUBSTITUTES: Livakovic, Corluka, Kovacic, Brozovic, Kalinic, Jedvaj, Bradaric, Caleta-Car, N. Kalinic, Badelj, Pjaca, Pivaric
NIGERIA: Uzoho; Abdullahi, Ekong, Balogun, Idowu; Etebo, Ndidi; Mikel, Iwobi, Moses; Ighalo
NIGERIA SUBSTITUTES: Ezenwa, Akpeyi, Ebuehi, Musa, Ogu, Nwankwo, Onazi, Omeruo, Awaziem, Iheanacho, Echiejile, Obi
The outcome of this contest was largely predictable since that penalty was converted. Nigeria could well have got something from the contest had they shown the slightest bit of endeavour. Croatia picked them up when necessary and have come away with a functional win that takes them top of Group D, ahead of Argentina, Iceland and the Super Eagles. That is going to be all from me tonight, thanks for joining us!
90+4 min FULL TIME: CROATIA 2-0 NIGERIA
90+2 min This game is meandering towards the inevitable. Nigeria have been shocking. They have been far, far removed from international standards tonight. It's been totally underwhelming from the Super Eagles.
90 min We are going to have four minutes of additional time here...
88 min Clever from Modric as he shows quick feet to buy a cheap free kick off a retreating Ndidi. That is just taking more time out of the game.
86 min Nigeria are finally starting to show some of that energy from the early stages of the half, but is has come about 25 minutes too late. Croatia are sitting deep without too many issues now.
83 min Greater tests clearly await Croatia and it has been rather strange how they have been able to secure three points here without really moving out of second gear. Iceland might still fancy themselves after picking up that standout point against Argentina earlier today.
81 min The substitutions have all but killed the game now. Nigeria look disjointed, while Croatia are more than happy to slow the tempo down as much as is humanly possible in this sport.
79 min Quick feet from Rakitic allows the playmaker to break through the Nigeria ranks before being brought down 30 yards out from goal. The resulting free kick is easily gathered by Uzoho, though.
77 min SUBSTITUTION: Here comes another change from Croatia, promising midfielder Mateo Kovacic takes the place of Rebic.
75 min Croatia are simply walking to the finish line now as they knock the ball about inside their own half. Nigeria have been totally missing when you take into account this 70-odd minute showing.
73 min Croatia are two up and they have done very little to break down Nigeria tonight. Iceland and Argentina will not be this forgiving you have to think when they meet later in the group.
71 min Absolute madness from Nigeria and this just about sums up a confusing showing from the Eagles. A cross comes into the box and for some unknown reason Troost-Ekong decides to wrap Mandzukic up in a full-nelson hold. The referee spots it with ease and signals straight for a penalty. Modric steps up to send the keeper the wrong way and essentially seal three points for Dalic's side.
71 min GOAL! CROATIA 2-0 NIGERIA (LUKA MODRIC, PENALTY)
70 min PENALTY TO CROATIA!
68 min Nigeria are still in this as long as Croatia continue to show such little ambition going forward...
66 min Croatia appear caught in two minds at the moment. This game has been there for the taking since the one-goal lead was achieved, but thus far Dalic's men have sat off for much of the second half.
64 min Very little happening in open play at the moment, although another corner soon sees Mandzukic climb highest to send a header over the goal frame.
62 min SUBSTITUTION: Nigeria make a change too. Iwobi is swapped out for Leicester City forward Ahmed Musa.
60 min SUBSTITUTION: It's Croatia who make the first change as forward Kramaric is replaced by Inter Milan creative midfielder Marcelo Brozovic.
59 min Left-back Idowu is given too much space on the wing and the Nigerian sends a smart ball into the box. Ighalo wins it but the effort flies straight into the grasp of Subasic.
57 min That just goes to show the glimmers of quality nesting in this Croatian side that can kill the game in an instant. Nigeria have improved already in the second half, but Dalic's men have the ability to conjure chances out of seemingly sterile conditions.
55 min MISS Croatia should double the lead... Perisic crafts the most wonderful cross from the left flank to find Rebic in the middle of the box. The striker opens up to send a finish beyond Uzoho, before seeing his effort somehow fly over the bar. That was a borderline sitter for the youngster.
54 min Central to this slight upturn for the Greens is Ndidi breaking forward into space a little more often. This time his movement releases Moses down the right wing, whose cross soon wins Nigeria another corner. The resulting ball comes to nothing, however, as Croatia clear at the far post.
52 min This is more like it! Iwobi races down the outside left to pick up a threaded ball from Ndidi and he then shows great footwork to beat his marker. Fortunately for Croatia, Lovren is there to block his shot in front of goal.
50 min Croatia make their first foray forward in the second period and the ball is soon cleared to Rakitic, who picks up possession around 35 yards out from goal. The playmaker opts for something special, although his shot is always rising and flies over the bar.
49 min There's certainly more energy from the Eagles early on. Moses breaks off the right to collect Etebo's cunning pass, but the winger drags his shot wide of the near post without testing Subasic.
47 min A bright start sees Nigeria scamper forward to win a corner. The set-piece is sent towards the front post for Idowu, leaving Perisic to make a vital challenge and prevent the defender from having a free header at goal.
46 min SECOND HALF! Croatia start the second half with a 1-0 lead. Nigeria need to improve quickly, but will they?
Croatia have the lead then in rather fortuitous circumstances, but Dalic's men just about deserve it having dominated much of the opening half. Nigeria have offered very little going forward and Croatia have been far too comfortable at the back.
45+2 min HALF TIME: CROATIA 1-0 NIGERIA
45 min CLOSE! The Chelsea man sends the ball in where it is soon cleared into the path of Iwobi on the edge of the area. The winger puts his laces through it only to see Lovren pull off a rather special block to protect Subasic from being tested.
44 min Moses shows great feet on the right and he is able to buy a timely free kick off Rebic, leaving Nigeria with a free kick in a promising position...
42 min Croatia have put together the best part of 225 passes in this first period and that perhaps gives you some indication of their possessional dominance. Perisic does brilliantly this time to head down for Mandzukic, who then lays it off for Vrsaljko who is breaking forward from right-back. The Atletico Madrid man's shot is a poor one though, as the effort goes flashing wide of the target.
40 min CHANCE! Nigeria step off just a little too easily and Modric is left free to whip a cross into the box. It's Kramaric who gets his head onto it in the middle of the box, but his deft header goes flying over the bar with Uzoho looking worried.
38 min Kramaric has been the real spark so far for the Croatians. This time the forward shows some skill on the right to beat Ndidi, although the eventual cross into the box is headed away at the first time of asking by Balogun.
36 min Nigeria have so far suffered from a link between midfield and attack. Ighalo is fighting valiantly for whatever is thrown forward, but a lack of support is seeing the ball come straight back at them.
34 min Croatia have at times threatened but they are fortunate to go in front. Dalic's men have responded by taking possession and knocking the ball around the back as they try to consolidate the lead.
32 min This has to hurt for the Nigerians. Croatia send a corner into the middle of the box where Manduzkic is able to get a head onto the cross. The effort looks to be flying wide of the far post, but it soon cannons into Etebo and past a helpless Uzoho. This game needed a goal although that was a tough one to take for the African side.
32 min GOAL! CROATIA 1-0 NIGERIA (MARIO MANDZUKIC)
31 min YELLOW CARD! First one of the game then as Rakitic flies into Moses after losing the ball cheaply. At times the playmaker is looking a tad frustrated at the lack of movement in front of him.
30 min Rebic has been promising. This time the winger peels cleverly off the back of Idowu to get the better of the full-back. The youngster then gets his head up to cross but his final ball is unable to provide for the limited options in the middle.
28 min A straight ball is driven into the feet of Mandzukic, who is unable to bring the pass under control and bring his teammates into play. The forward has been rather quiet thus far.
26 min So far, so good then for Nigeria who seem happy to wait for the counter. Croatia have enjoyed most of the possession in the opening period but have been able to do very little with it. If the Europeans are to take the lead it might just come through an individual moment of brilliance.
24 min Glimmers of Croatian quality are just starting to cut through. Rebic does brilliantly down in the right corner to get the better of Idowu with some clever feet, however the resulting cross into the mixer is a tame one leaving Troost-Ekong to clear.
22 min Nigeria move forward with a rare counter down the right channel. Iwobi cuts inside into the box before seeing his shot blocked by Vrsaljko. The resulting corner soon sees a loose ball fed into Etebo, but he can only send a wild effort wide of the target from range.
20 min Kramaric is beginning to tick now as he turns and drives at the Nigeria defence, before being brought down by Balogun on the edge of the area. Modric sends the free kick towards the back post, where Uzoho comes coolly off his line to gather and thwart the danger.
18 min Poor from Modric this time as Croatia get the chance to send in another corner. The ball does not evade Shehu at the front post and Nigeria are able to clear with relative ease.
16 min Nigeria will need to be wary of this. The Eagles sit back and give Kramaric time on the ball, allowing the striker to wind up from distance and drive a shot down low just wide of Uzoho's near post.
14 min CHANCE! This is lovely stuff from Croatia. Modric drives in off the left flank before feeding a ball into Rebic. The frontman stops the pass dead on the edge of the box, allowing Perisic to drive onto the set ball. The Inter Milan man opens up to lash a testing shot that flies just inches over the crossbar.
12 min Nigeria claim a free kick just inside the Croatia half and the Eagles look to bypass the build-up play by sending a long ball into the box from Moses. Croatia stand firm, though, as Vida heads clear.
10 min Jeers ring out around the ground as Croatia step off the gas and allow Nigeria to move the ball slickly across the deck. Around 80% of fans in this stadium are from Croatia this evening. Nigeria do not look too perturbed, however. Not the most exciting of starts, but an intriguing one nonetheless.
8 min Rakitic is brilliant at this. Perisic drifts off his marker on the left flank, leaving the Barca playmaker to pick out the winger with a huge, raking ball out wide. Shehu does well to steer the ball away for a corner, though. Croatia cannot make anything of the set-piece as Balogun swings clear in the box.
7 min Croatia appear happy to take a good look at this Nigeria side as they move possession across the pitch. No real attacking intent from either side thus far as they seem to be sizing each other up.
5 min Some gaps are already starting to appear in the middle of the park and both Rakitic and Modric are looking to get on the ball just inside the Nigeria half. Nigeria are showing plenty of energy, but Croatia have held more of the positive possession.
3 min The Super Eagles appear to have settled comfortably, but Perisic gives them a wake-up call as he scampers away on the break down the left channel. The winger turns a ball into the middle towards Mandzukic, although Troost-Ekong is able to clear.
2 min Nigeria get an early chance to put a teasing ball into the box from a Moses free kick, but Lovren rises highest to head clear under pressure from Iwobi.
1 min KICKOFF! Here we go then, Nigeria get things moving in Kaliningrad...