The African nation kick-started their World Cup bid - and it's Argentina next for the Super Eagles.
Ahmed Musa was restored to Nigeria's starting XI with devastating effect as he scored both goals to help them resuscitate their World Cup hopes.
Left out of his country's opening Group D game at the tournament in Russia, Musa showed his worth with two outstanding strikes that put the Africans back in contention for a second round place.
The opening goal, soon after a drab first half, saw him pluck the ball out of the air with his first touch before blasting it home.
The second goal came in the 75th minute, when after a break down the wing, Musa cut inside and waltzed around the goalkeeper before firing the ball into the net.
Iceland's Gylfi Sigurdsson shot an 82nd minute penalty over the top of the bar, denying his team a chance to try to force a late comeback.
All three other teams in the group remain in the hunt to go through with Croatia, but Argentina and Iceland know they have to win to have any chance of progressing.
- Gylfi Sigurdsson82'
Well that result has blown this group wide open! Croatia have confirmed qualification, but each of the other three nations can still make it to the knockout stages. Musa hit an outstanding double, rifling home after Moses' pacey counter-attack, before cutting inside from the left and rounding the goalkeeper for the second. Gylfi Sigurdsson missed a late penalty - awarded courtesy of VAR - as Iceland desperately searched for a way back into the game, but they just couldn't muster enough going forward. It finishes 2-0 to Nigeria!
FULL-TIME: NIGERIA 2-0 ICELAND
BLOCK! Ighalo wins a long ball and holds it up against Ingason, before laying off to Iwobi, whose shot is blocked away from the edge of the area!
Mikel is back on, albeit still clutching his injured wrist. Just one minute to go.
Mikel is down holding his wrist, and it doesn't look good for him. Nigeria have used all three substitutions, however, so he'll either have to continue or his side will have to play the remaining two minutes with 10 men.
A flowing Iceland attack results in Saevarsson placing a low cross into the middle, but it's scrambled away by the Nigerian defence.
Nigeria look confident and composed now, while Iceland look frustrated. They just can't seem to create any real openings to haul themselves back into it. That missed penalty has undoubtedly cost them dear.
Etebo comes off for Iwobi in a surprisingly attacking move by Rohr, sacrificing a holding midfield player for a creative forward in the form of the Arsenal man.
Iceland's day in a nutshell
A look at Sigurdsson's penalty miss...
And he appears to be leaning back too much!
Gunnarsson now makes way for Skulason as Iceland search desperately for an equaliser.
What scoring a brace in the World Cup feels like!
CHANCE! Musa wriggles inside from the left and feeds Iheanacho, who lines up a left-footed effort from outside the box that is blocked behind for a corner!
That shot is Iheanacho's last meaningful contribution to the game as former Watford striker Ighalo replaces him.
PENALTY MISSED! Gylfi Sigurdsson goes for the top-right corner and fires it over the bar! He took a short run-up and watched the goalkeeper dive the wrong way, but couldn't hit the target! That might put an end to Iceland's comeback hopes.
PENALTY! Finnbogasson races into the box and Ebuehi clips him at the byline! The referee doesn't give it initially, but following a VAR check, the referee points to the spot!
Iceland lok a little shellshocked. They're still pushing forward to try and get something from this game, though.
Omeruo played a long ball down the line, and Musa had a great deal to do from there, but he showed incredible pace and composure to pull it off!
GOAL!!!! MUSA STRIKES AGAIN! NIGERIA GO 2-0 UP! Musa races down the left and beats a defender for pace, before cutting inside and rounding the charging Halldorsson. He then keeps his composure, picking his spot and rifling it into the top corner!
CROSSBAR! Musa rattles the crossbar with a wicked, curling strike that fools the goalkeeper into committing to his left while the strike comes back into the middle, but it clatters back off the bar!
Bodvarsson comes off for Sigurdarson in a like-for-like change up front by Hallgrimsson, who looks to inspire his side to an equaliser.
MISS! Troost-Ekong throws himself at a cross from the right, but he can only head wide from a difficult angle.
Ingason shows great bravery to come out and block a powerful Etebo strike from outside the box. The midfielder had all the time in the world there to line up his strike.