DOHA: Lionel Messi says Argentina's World Cup campaign has now truly started after inspiring his side to a 2-0 win over Mexico to prevent an early elimination from the competition.

Following a shock 2-1 loss to Saudi Arabia in their opening Group C match, Argentina entered Saturday's clash with Mexico knowing defeat would see them unable to advance.

Lionel Scaloni's men struggled to get going in the first hour of the match at Lusail Stadium before Messi found the bottom-right corner from 25 yards.

The Paris Saint-Germain forward then picked out Enzo Fernandez for the substitute to score a delightful late second for Argentina, who join Saudi Arabia on three points.

La Albiceleste meet Poland, who are one point better off at the top, in their final game and will be guaranteed a place in the last 16 with victory, while a draw may also be enough.

Messi is glad to have responded to the defeat against Saudi Arabia but stressed there is still plenty of work for his side to do if they are to reach the knockout stages.

"Another World Cup started for us today," he said.

"There were many factors behind the [Saudi Arabia] defeat, such as players playing at a first World Cup and the schedule.

"These are not excuses, but we knew we had to win today. We had to play the way we did because Mexico performed well and have a great coach.

"We calmed down a lot more in the second half and got the goal we needed. We can't give up now; we have finals from this point on and can't make a mistake."

Messi was also on target against Saudi Arabia and has now scored in six successive appearances for Argentina, making this his joint-best ever run for his national team.

The seven-time Ballon d'Or winner took his goals tally in the competition to eight, putting him level with Diego Maradona and behind only Gabriel Batistuta (10) for Argentina.

He is both the youngest (18 years, 357 days v Serbia in 2006) and oldest (35y, 155d v Mexico) player to score and assist in a single World Cup game since such records began (1966).

"He showed that in the space of 30 seconds or so he can be very harmful," said Mexico head coach Gerardo Martino, who previously managed Messi for club and country.

"They found Messi on his own and he scored from distance. He didn't find space often, but I understand a goal changes the perspective of what's happened over the game."

Mexico must now beat Saudi Arabia and hope Argentina lose to Poland if they are to go through, while a win for Mexico and a draw in the other game will take it to goal difference.

"As long as there is a chance we will try," Martino said. "We need to score goals and I believe in life those who compete on a daily basis are used to bouncing back."

Argentina's tense win was played out in front of a crowd of 88,966, with that the highest for a men's World Cup match since the 1994 final at California's Rose Bowl (94,194).

The match was far from a classic, the nine shots produced by both sides combined being the lowest tally in a World Cup game since 1966.

But head coach Scaloni is glad his side did what was required of them to stay in the hunt for a third world crown on the back of lifting the Copa America last year.

"We knew this would be a tough game," he said. "The first half wasn't good from either side. We made some adjustments at half-time to get Lionel more space.

"We were able to have players in the middle of the pitch winning duels and then you know what happened. Our number 10 scored the goal and does what he does best.

"Messi should enjoy this World Cup, and the fans too. But we still have another game and must keep our feet on the ground, stay humble and work hard.

"Just like when we won the Copa America, we'll go again tomorrow. Happiness lasts only 10 minutes. We have to find the right balance."