Barcelona coach Luis Enrique lauded the "decisive" Lionel Messi for his hat-trick against Manchester City in the Champions League.

Messi scored three times and set up Neymar for another in a resounding 4-0 victory for Barca at Camp Nou on Wednesday.

Luis Enrique was full of praise for the Argentina star, who was making just his second appearance back from a groin injury.

"He was decisive. He was involved in all the game's key moments," he said, via the club's website.

"Messi finishes as if he were playing on the school playground."

He added: "It doesn't matter if he's coming off an injury. It's just the way he processes the game."

Messi had given Barca the lead before Claudio Bravo was sent off, and he struck twice more prior to Jeremy Mathieu also seeing red.

Luis Enrique felt the red card to Bravo was game-changing, with Messi later setting up Neymar – who had missed a penalty – for the sealer.

"City is a team that's constantly changing things up during the game. It's tough to play against them," he said.

"City were good until the end of the game; the expulsion changes the match."

Barcelona are top of Group C on nine points, five clear of second-placed City through three games.