Peru missed a second-half penalty in a 1-0 loss to Argentina in Buenos Aires.
The results leave Brazil in top spot with 28 points, six ahead of Argentina.
Argentina failed to score for the first time since June, 2019.
The announcement comes after both European governing body UEFA and their South American counterparts CONMEBOL came out strongly against FIFA's plans for a biennial World Cup.
Everton Ribeiro got his second goal in two games to help Brazil on their way to a 2-0 win over Peru in another World Cup qualifier.
Aston Villa goalkeeper Emiliano Martinez and Tottenham duo Cristian Romero and Giovani Lo Celso were on the pitch as part of the Argentine line-up when officials from Brazil's health regulator Anvisa invaded the pitch and stopped the game.
Five-time world champions Brazil have 21 points, six more than Argentina in second place.
The striker joins Blasters on loan from Agentine side Club Atlético Platense until June 30, 2022.
"It's an ambitious club. You can see they're ready to fight for everything," Messi told a news conference.
Messi will wear the number 30 shirt, the club confirmed in a video posted on its Twitter feed, headlined "a new diamond in Paris".