Philippe Coutinho and Neymar bailed Brazil out with stoppage-time strikes against Costa Rica following another uninspiring display at the 2018 World Cup.Coach Tite's team were heading for a second inglorious draw when Barcelona midfielder Coutinho popped up to poke home from Roberto Firmino's nod down.
And with seconds remaining Neymar, the world's most expensive player, tapped in Douglas Costa's cross to secure Brazil's first win of the tournament.
Their hopes of victory looked to have been dashed when they had a penalty decision overturned by VAR in the 78th minute after referee Bjorn Kuipers had initially ruled Neymar had been brought down in the area.
As it stands Brazil currently lead Group E and could go through with a draw in their final pool match against Serbia.
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 - when Gylfi Sigurdsson fired over.
The result gives a slight lift to beleaguered group rivals Argentina. Victory over Nigeria in their final game would see La Albiceleste safely into the last 16 - as long as Iceland do not beat group leaders Croatia. In that event, goal difference would decide who progressed.
Victory in that game for Nigeria, on the other hand, would now guarantee their progress. Having started the day bottom of the group, they find themselves second - three points behind Croatia, who have already qualified for the knockout stage.
Switzerland took a huge step towards the last 16 of the World Cup as Xherdan Shaqiri scored a brilliant solo 90th-minute winner against Serbia.
The Stoke City player collected the ball near the halfway line before dribbling away from the defence and slotting past Serbia goalkeeper Vladimir Stojkovic.
Granit Xhaka had scored a brilliant equaliser for Switzerland after Aleksandar Mitrovic put Serbia in front with a header in the fifth minute.
Serbia, who had a strong claim for a second half penalty turned down, had dominated the first half, knowing a win would have confirmed their place in the knockout stages.
Switzerland are now level with Brazil on four points at the top of Group E, in second place due to an inferior goal difference.
They will qualify for the last 16 with a draw against Costa Rica, who have already been eliminated, in their final game.
If Switzerland win, Serbia must beat Brazil in their final game to progress.