Both teams have Mexico and Poland to come, with Argentina needing an immediate reaction if Messi is to have a realistic chance of matching Diego Maradona’s immortality in his homeland by bringing home the World Cup.

The result revived old question marks over Argentina’s defence and broke their amazing 36-match undefeated run. That stopped them from matching the previous international record of 37 games unbeaten held by Italy.

It also marred Messi’s achievement of becoming the first Argentinian to score in four World Cups on his 20th appearance in the tournament. Only Maradona has played more games for Argentina at the World Cup, 21 in all.

“This hurts a lot. We were dreaming of starting the World Cup with a win,” said Messi’s strike partner Martinez. “But it’s happened and now we have to train and think forward.

“We lost this game because of our own mistakes, most of all in the second half. There are details that make a difference and we need to correct our mistakes.”

It had all looked so different at the start when the marauding Messi nearly scored in the opening seconds, celebrated joyfully after sending Saudi goalkeeper Mohammed Al-Owais the wrong way with his penalty, then had another goal disallowed.

For the Saudis, the result buried their dismal history at the start of tournaments, including a 5-0 thrashing by hosts Russia in 2018 and an 8-0 pummelling by Germany in 2002.

Their feat against the two-time World Cup winners and current South American champions was all the more remarkable given the departure of their influential captain and midfielder Salman Al Faraj just after halftime, clutching a hamstring.

Argentina’s last defeat was by Brazil in the semi-finals of the Copa America in July 2019. They are ranked third, 48 places above Saudi Arabia, by world football’s governing body FIFA.