Lionel Messi made his Paris St-Germain debut as a 66th-minute substitute in a 2-0 win at Reims in Ligue 1.
The Argentine, wearing his new number 30 PSG shirt, received a standing ovation as he replaced his friend Neymar in front of a sell-out crowd.
It was the first club game of his career for a team other than Barcelona.
“He is still far away from his best form but he has been training well and he will be fit in the next two weeks,” boss Mauricio Pochettino told Reporters.
“We are waiting for the best from him. I’m very happy that he made his debut. It was very important for him.
“He was good, from his first touches he gave the team peace of mind. It’s good for him to start with a win.
“It was good to hear the crowd cheering for him, not just our supporters, it’s something Leo has earned.”
Kylian Mbappe scored both goals on what could be his final appearance for the club, with Real Madrid keen to sign him before Tuesday’s transfer deadline.
Real Madrid has made a 160m euro (£137m) bid to sign the 22-year-old, who has now scored 135 goals in 175 games for PSG.
His first goal was a header from an Angel di Maria cross and for his second, he swept home Achraf Hakimi’s cross.
“Kylian is our player and you know that in football and business, there is always gossip and rumours,” Pochettino said.
“I think our President and our sporting director were very clear and he is still here. I am really happy to have Kylian.
“He is one of the best, one of the most important players in the world today, and for him to be with us is a gift.”
But the headlines will be about 34-year-old Messi, who came on moments after that second goal.
Tickets for the game were being resold for about 6,000 euros after Reims sold over 20,000 tickets for the Stade Auguste-Delaune match. Before Messi’s signing, only about 6,000 had been sold.
Their purchasers may have been disappointed to see Messi only named on the bench – although, he got an ovation as he warmed up, with fans chanting his name, and an even bigger one when he came on.
He played some nice passes and was involved in good link-up play, drawing several fouls. However, he had few touches in the penalty area and no shooting opportunities.
“He brings serenity to the team. His energy and his optimism trickle down on the rest of the team,” said Pochettino.
Messi had missed the first few games for PSG since his free transfer move, following his exit from Barcelona. This was his first game since winning the Copa America with Argentina in July.
He joined Barcelona as a 13-year-old and scored a record 672 goals in 778 games for the club.
He has won six Ballons d’Or – also a record – and is considered one of the greatest footballers.