Lionel Messi (No.10) of Argentina leaves the pitch following their defeat in the FIFA World Cup Group C match against Saudi Arabia at Lusail Stadium in Lusail, Qatar on November 22, 2022. Photo: VCG

Unheralded Saudi Arabia notched one of the biggest shocks in World Cup history on Tuesday with a 2-1 win over Lionel Messi's Argentina thanks to a scintillating second-half comeback.

On his fifth and final quest for the only major trophy to elude him, the 35-year-old Messi scored a 10th-minute penalty in a dominant first half display where he and Lautaro Martinez also had three goals disallowed for offside.

But Saudi Arabia, the second-lowest ranked team in the tournament after Ghana, threw caution to the wind at the start of the second half, charging at Argentina's defense in front of a frenzied 88,012 crowd.

First, Saleh Al-Shehri squeezed in a low shot in the 48th minute. Then, to the disbelief of even the Saudi fans, Salem Al-Dawsari curled in a scorching strike from the edge of the penalty area in the 53rd minute to leave ­Argentina and Messi looking utterly shell-shocked in the Group C opener.

Despite plenty of possession after that, Argentina could not penetrate the Green Falcons, who were competing in their sixth World Cup but had never previously won an opening game.

The entire game was played in an extraordinary atmosphere at the Lusail Stadium, with Argentina's traditionally massive and raucous following matched by the thousands of Saudis who had come over the border to cheer on their team.

"Our team fulfils our dreams!" and "Where is Messi? We beat him!" the green-clad Saudis chanted over and over in the Lusail ­Stadium, on their feet and greeting every clearance - including one headed off the goal line - with a deafening roar.

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 defense 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 on Tuesday 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.

Lionel Messi lamented Argentina's shock second-half capitulation but said he was not surprised by the threat from opponents 48 places lower in the world rankings.

"It's a situation that this group of players has never been through. It's been a while since we suffered such a tough blow. We didn't expect to start like this," Messi told Argentinian media after the defeat.

'We're OK'

In the second half, "in five minutes of mistakes that we made, we went 2-1 down and then it was really tough and we lost organization and started punting the ball," he said in comments broadcast by Todo Noticias.

"It's up to us to fix what we did wrong and get back to the basics of who we are," said Messi.

"We're OK, obviously hurt by the result, very bitter. But people must trust that this team will not let them down and we are going to go for it in the next two games. We've played games of this nature before and we're going to perform well.

"Now's the time to be more united than ever, to show how truly strong we are."

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 twice 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 semifinals of the Copa America in July 2019. Their last defeat in their opening match at a World Cup was against Cameroon in 1990. In potentially a good omen for Messi and his teammates, they still made it to the final then.