Manchester City took a big step towards their first Champions League final as goals by Kevin De Bruyne and Riyad Mahrez earned them a 2-1 comeback win at Paris Saint-Germain in the semifinal first leg on Wednesday.

PSG went ahead courtesy of a Marquinhos header in the first half, but Mauricio Pochettino's side lost control after the break with De Bruyne and Mahrez finding the back of the net in the space of eight minutes to secure City's 18th consecutive away win in all competitions.

Last year's runners-up PSG then found themselves down to 10 men as midfielder Idrissa Gueye picked up a straight red card in the 77th minute for a reckless challenge on Ilkay Gundogan.

"The second half was much better; the way the first goal went in was a little bit lucky, but we played great football in the second half, we did well," De Bruyne said.

Next Tuesday, Man City will need to show the same away form that enabled them to beat Barcelona at Camp Nou and Bayern Munich at the Allianz Arena in previous rounds if they are to progress.

"At half-time, I told the players we needed to be ourselves. We needed to be more aggressive, and we didn't let them breathe after the break," City manager Pep Guardiola said.

Guardiola added: "I told them 'I understand you guys, I was a player myself. If you lose you lose but you have to try to play our game. What is our identity as a team without the ball and with the ball'?"

Bernardo Silva explained to ESPN: "[Guardiola told City at the break] that we have to have the ball more, that we have to enjoy more, that we have to try to press them more.

"We know that when you play against a great team like PSG, you are not going to have the ball the whole 90 minutes. You know that you are going to have periods in which you are going to be better than them and others in which you are going to be not as good.

"We are very happy to have materialised those moments in which we had been on top by scoring two goals. Now there are 90 minutes to play and there is still a very tough path ahead."

Pochettino agreed the visitors were the better team after the interval.

"The key was that we didn't show the same energy with the ball than in the first half," Pochettino said after the match.

"But we are confident that we can turn this around and approach the second leg the same way. The first half showed that we were right in our approach of the game.

"We just have to keep the same intensity with the ball. That's what we have to improve."

Marquinhos said that PSG needed more composure.

"Sometimes you have to be strategic and intelligent. We conceded two really stupid goals. These are details that will count," he said.

"Above all, we need to have personality. We have to have the mentality to win, to do whatever it takes to get through. We are very close, it's not the time to have doubts."

City dominated the early possession, but PSG were the more dangerous side with Neymar testing City goalkeeper Ederson twice.

Marquinhos, returning to the team from an injury suffered in the quarterfinal first leg against Bayern Munich, put the hosts in front when he headed home Angel Di Maria's whipped corner in the 15th minute.

City, overly cautious for fear of being punished on the break, were again exposed on a set piece when Leandro Paredes headed Neymar's corner just wide.

Guardiola's City side lacked their usual composure, with Joao Cancelo picking up a yellow card for a challenge on Kylian Mbappe.

City's first real chance came in the 42nd minute when Phil Foden, played infield by Silva, shot too close to PSG goalkeeper Keylor Navas.

The visitors were more attack-minded in the second half, and they equalised after 64 minutes when De Bruyne -- from a corner by Oleksandr Zinchenko, who had just replaced Cancelo -- sent in a cross and Navas failed to react as it curled into the far corner of the net.

Navas was beaten again seven minutes later when Mahrez's free kick flew through an inadequate PSG wall.

Gueye's dismissal for a wild tackle on Gundogan made City's task easier, and they will take a big advantage into the second leg in Manchester.