Saudi goalkeeper Mohammed Al-Owais produced a five star performance to help his team beat tournament favorites Argentina 2-1 in a Group C World Cup match played at Lusail Stadium in Qatar.
Lionel Messi had given Argentina an early lead against the Middle Eastern nation with a 10th-minute penalty.
The South Americans then had three goals chalked off for offside in the following 35 minutes, suggesting a heavy defeat for Saudi Arabia was likely.
But two goals in five minutes at the start of the second half turned the game on its head for a side that bookies were offering odds of 500-1 to win the World Cup before the tournament began.
Saudi had to hang on for around 14 minutes’ of added time before the referee blew the whistle for full-time, sparking delirious celebrations among their players and supporters in the Lusail Stadium.
The match was played in an extraordinary atmosphere, with Argentina’s traditionally raucous following matched by the thousands of Saudis who had crossed the border to cheer on their team.
“Our team fulfils our dreams!” and “Where is Messi? We beat him!” the green-clad Saudi fans chanted, greeting every clearance from their defence with a deafening roar
While Argentina dominated possession and forced saves from Saudi goalkeeper Mohammed Al-Owais, they failed to exert sustained pressure on the side ranked second lowest in the tournament, after Ghana.
Argentina were second favourites to lift the trophy before a ball had been kicked, having gone 36 matches unbeaten.
Their last defeat came three years ago, to Brazil.