Argentina’s Lionel Messi reacts his team lost to Saudi Arabia, 2-1, on Tuesday in Lusail, Qatar. Natacha Pisarenko/Associated Press

LUSAIL, Qatar — Lionel Messi stood with his hands on his hips near the center circle, looking stone-faced as Saudi Arabia’s jubilant players ran in all directions around him after pulling off one of the biggest World Cup upsets ever against Argentina.

The South American champions and one of the tournament favorites slumped to a 2-1 loss Tuesday against the second lowest-ranked team at the World Cup in a deflating start to Messi’s quest to win the one major title that has eluded him.

Asked how he felt after a painful start to his record fifth World Cup for Argentina, Messi said: “The truth? Dead. It’s a very hard blow because we did not expect to start in this way.”

Saudi Arabia’s comeback joins the list of other major World Cup upsets: Cameroon’s 1-0 win over an Argentina team led by Diego Maradona in the opening game of the 1990 World Cup; Senegal’s 1-0 victory over defending champion France in the 2002 tournament opener; or the United States beating England by the same score in 1950.

“We know the World Cup is this way,” Argentina Coach Lionel Scaloni said. “Sometimes you can steamroll the opponents and, in a couple of plays, you are losing.”

That summed up the pattern of a match that started with Messi giving Argentina the lead, calmly converting a penalty in the 10th minute for his 92nd international goal. It had all the makings of a routine win for the defending Copa America champions, who were on a 36-match unbeaten run – one short of the record in international soccer.

Didn’t turn out that way.

Goals by Saleh Alshehri and Salem Aldawsari in a five-minute span early in the second half gave the Saudis a landmark result in the first World Cup staged in the Middle East. Their previous biggest win was 1-0 over Belgium at the 1994 World Cup, secured by a storied individual goal by Saeed Al-Owairan.

“All the stars aligned for us,” Saudi Arabia Coach Herve Renard said. “We made history for Saudi football.”

The 35-year-old Messi, playing in his fifth – and likely his final – World Cup for Argentina, scratched the side of his head and shook hands with a Saudi coaching staff member after the final whistle.

He walked toward the tunnel with a group of other Argentina players and looked despondent, an all-too-familiar scene for the seven-time world player of the year who has yet to win soccer’s ultimate prize.

“We are facing two finals now,” said Argentina striker Lautaro Martinez, looking ahead of remaining group matches against Mexico and Poland. “We screwed it up in the second half.”

The unlikely victory by a team made up entirely of Saudi-based players was sealed by a somersault by Aldawsari, who brought down a high ball just inside the penalty area, spun his way past Nahuel Molina with the help of a ricochet, dribbled past Leandro Paredes and drove a powerful shot to the far corner in the 53rd.

TUNISIA 0, DENMARK 0: Arab teams are making an impact at the first World Cup in the Middle East.

Tunisia held European Championship semifinalist Denmark to a draw in Al Rayyan, Qatar, three hours after Saudi Arabia beat Argentina in a shocking upset.

Before a stadium filled almost entirely with Tunisia’s red-clad supporters, midfielder Aïssa Laïdouni set the tone in the very first minute when he stripped emblematic Denmark playmaker Christian Eriksen of the ball with an aggressive sliding tackle – then stood up and pumped his arms menacingly, gesturing to the crowd to get even more fired up.

“I’m always proud to represent Tunisia and we always go on the pitch 100% committed,” Laïdouni said through a translator.

Tunisia likely deserved more but an expert save shortly before halftime by goalkeeper Kasper Schmeichel helped Denmark preserve the draw.

Having already gone down to the grass after Tunisia broke through the defense, Schmeichel stuck his hand up to deflect a shot from Issam Jebali, who plays his club ball in Denmark for Odense.

MEXICO 0, POLAND 0: Robert Lewandowski’s second-half penalty attempt was saved by Mexico goalkeeper Guillermo Ochoa, leaving Poland to settle for a draw in Doha, Qatar, at the World Cup.

It was Lewandowski’s first penalty miss for the national team. Poland’s all-time leading scorer with 76 goals remains without a World Cup goal.

The Poland forward was awarded the penalty following a VAR review after Hector Moreno got hold of his shirt and pulled him down. Ochoa, playing in his fifth World Cup, came up yelling in celebration after his stop, sending the crowd into chants of “Memo!”

While Mexico dominated possession, Poland goalkeeper Wojciech Szczesny turned away all three of El Tri’s shots on goal.

The scoreless draw was good for Argentina, which was upset by Saudi Arabia 2-1 in an earlier Group C match. The Argentines, led by Lionel Messi, were widely considered to be the favorites to advance.

FRANCE 4, AUSTRALIA 1: France showed it can cope without its star striker at the World Cup.

Kylian Mbappe scored one and set up the second of Olivier Giroud’s two goals to help the defending champions beat Australia, in Al Wakrah, Qatar.

Giroud equaled Thierry Henry’s national record of 51 goals with a header from Mbappe’s cross in the 71st minute.

Moments earlier, Mbappe headed in Ousmane Dembele’s cross from the right to start this World Cup as he finished the last – with a goal. He knelt with one hand behind his back and his finger on his forehead in a new celebration.

Giroud didn’t even score at the last World Cup.

Craig Goodwin gave Australia the lead when he turned in winger Mathew Leckie’s cross in the ninth minute. France midfielder Adrien Rabiot equalized with a powerful header in the 27th and set up Giroud’s first goal shortly after.

France was playing without the injured Karim Benzema, who was ruled out of the World Cup last week.