Lusail, Qatar - Argentina suffered one of the biggest ever World Cup shocks with a 2-1 defeat by a brave Saudi Arabia in its opening Group C match on Tuesday morning!

Superstar Lionel Messi and his teammates were left stunned by the first defeat for Argentina in its World Cup opener since famously losing 1-0 to Cameroon in 1990.

For the Saudis, it was a maiden triumph in any of their World Cup openers and their first ever win against the South American side. It was also a major moment for the first Arab World Cup, following hosts Qatar flopping on the opening day.

Messi broke the deadlock for Argentina from the spot in the 10th minute as his team seemed to have the game under control as they targeted a record-equalling 37th international match unbeaten.

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But they were soon frustrated as Messi and Lautaro Martinez (twice) were tricked by a strong Saudi defensive line and saw their goals ruled out for offside.

Argentina held on to their lead until the break but was shocked in the 48th minute when Saleh Al-Shehri, Saudi's top scorer in qualifying, beat a sleepy defense to equalize.

It got even worse five minutes later, when Salem Al-Dawsari took a rebound and curled the ball into the top corner to put the team ranked 51 in the world into the lead over one of the tournament favorites.

Saudi keeper Mohammed Al-Owais was also crucial to the triumph, after he made fantastic saves to deny Nicolas Tagliafico from close range and a late Messi header.

Abdulelah Al-Amri was also a key to the win as he prevented an Argentina equalizer by clearing the ball off the line in added time.

The eight minutes of stoppage time indicated by the referee turned into an extra 14 minutes played after Saudi defender Yasser Shahrani went down after being hit by Al-Owais' knee.

There was a lot of concern, but the player signalled he was OK as he was carried off on the stretcher.

The late drama and the extra minutes, however, were not enough for Argentina to find a late equalizer in one of the competition's biggest ever shocks, matching Argentina's 1990 defeat as holders and possibly even the USA's legendary 1-0 defeat of England in 1950.

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The only consolation for Argentina is that they still reached the 1990 final.

"We lost due to our own mistakes. We could have scored more than one goal in the first half," Martinez said after the huge upset. "The defeat hurts a lot because we wanted to start the World Cup with a victory. We need to rest and think about fixing the mistakes."

The other Group C game between Mexico and Poland kicks off at 11 AM EST.