A 2-nil win for Nigeria vs Iceland has left the battle for 2nd place in Group D wide open and has given Argentina a chance, if they can beat Nigeria on Tuesday.
The win now means Nigeria moves second in Group D on 3 points, behind Croatia on 6 points, while Iceland and Nigeria are on 1 point each.
Nigeria play Argentina on Tuesday and will qualify if they win and Croatia either beat Iceland or the match ends in a tie.
Nigeria can qualify with a win or tie against Argentina if Iceland loses or ties with Croatia.
Both games will be played simultaneously at 2pm Tuesday.
Ahmed Musa scored both goals as Nigeria swept aside World Cup debutants Iceland to leave Group D intriguingly poised with one round of games to go.
The Super Eagles would have gone out with defeat but came good in Volgograd.
Musa showed superb technique to fire Nigeria ahead on the half-volley before the Leicester player rounded keeper Hannes Thor Halldorsson to make it 2-0.
Iceland missed a late penalty awarded after a video assistant referee review, Gylfi Sigurdsson firing over.