Having been stunned by Saudi Arabia in their opening game earlier in the week, Argentina knew a second successive defeat would have seen them knocked out of the tournament with a game to spare.
However, Messi’s sensational opener on 64 minutes and substitute Enzo Fernandez’s fine curling effort earned a 2-0 win and Lionel Scaloni’s men can secure a place in the last-16 by beating Poland in their final game on Wednesday.
"Today starts another World Cup for Argentina," Messi said. "I tell people the same thing, that they continue to believe. Today we did what we had to do.
"We had no other choice. We had to win so that we depended only on ourselves.
"The first half we didn’t play as we should and in the second, when we calmed down, we started to play the ball better and until the goal we went back to being what we are.”
Lionel Scaloni made five changes to the XI that had started the defeat to Saudi Arabia, Argentina’s first since July 2019.
Scaloni also made a number of in-game shifts in formation but refused to credit the with victory, instead pointing to the brilliance of Messi.
“Messi scored the goal and he did what he does,” Scaloni said. “The important thing is to enjoy this World Cup. Messi should enjoy this World Cup and all the fans enjoy seeing him play.
“The locker room was feeling well at half-time bearing in mind how difficult the game was. We didn’t expect to be 3-0 up at half-time. We asked for patience.
“Today the game changed but I don’t think it was down to fine details. It was because, on top of having other great players, we have Leo.”