Lionel Messi was motivated to become "even bigger than he is" against Australia due to a confrontation with Aziz Behich moments before his goal, according to Alexis Mac Allister.

Argentina captain Messi inspired his side to a 2-1 win in the last 16 of the World Cup on Saturday, booking a quarter-final against the Netherlands.

The legendary forward had endured a quiet start to the match, with Argentina struggling as a result, but he burst into life 10 minutes before half-time.

Messi pressed Behich in the corner of the pitch and won an Albiceleste throw-in, with the pair then tangling in a brief tussle.

Within seconds, Messi had fired a precious opener, his first World Cup knockout goal in his ninth such match.

"Leo, when these things happen, he brings out that inner fire that he has, that personality that makes him even bigger than he is," team-mate Mac Allister said. "In these kind of games, he becomes bigger.

"For us, he is the most important player. He knows it, he helps us a lot, and for us, it is a pride to be able to accompany him.

"We know that he always tries to give his best, but when something happens [like the confrontation] he has enough personality to get out of it, to make it work for him and start playing even better."

Messi was involved in everything Argentina did going forward, attempting six shots and creating four chances – two high marks across the match.

That made Mac Allister's job simple: give Messi the ball.

"I really enjoy playing with Messi," the Brighton and Hove Albion midfielder said. "For me, he's the best player in history, in the world, and I'm proud to be next to him.

"I try to give him the ball to him, because if the ball goes through him, everything is easier. I think he's having a great World Cup and we need him a lot."