"A game of two halves." Rarely in Manchester City's history has this expression made so much sense.

Like they were in Dortmund, in the quarterfinal second leg when they were 1-0 down at half-time and facing the prospect of a disappointing Champions League exit, Pep Guardiola's players were behind against Paris Saint-Germain in the French capital on Wednesday in their semifinal first leg. Deservedly behind, too. The Parisians were too good for City's press, buildup and movement. But again, like all great teams do, they fought back.

Man City showed their character and found a way of not just getting back into the game, but forcing PSG into mistakes that cost them two goals. From being almost unable to create anything in the first 45 minutes, which was so unlike City, the second 45 minutes were everything this team is about: intensity, pressure, aggression and intelligence. Suddenly, it was PSG who were unrecognisable.

- Stream ESPN FC Daily on ESPN+ (U.S. only)
- ESPN+ viewers guide: Bundesliga, Serie A, MLS, FA Cup and more

The Premier League leaders played much higher up the pitch, finally got full-backs Kyle Walker and Joao Cancelo involved, and Kevin De Bruyne was more prevalent. They took the ball away from PSG, preventing them from playing out from the back as well as they did in the first half. Without the ball, there is not much Marco Verratti, Neymar and Kylian Mbappe can do. City made them chase after the ball instead of having it at their feet, and it made all the difference in a 2-1 victory.

The character showed by Guardiola's players to come back into this game, to boss the second half in the way they did, is deserving of high praise. And when you are on top but still trailing 1-0, you need your best players to step up -- and City's did.

This was a special night for Riyad Mahrez. He was back home, in Paris, where he was born and raised. The Parc des Princes is a stadium he used to visit when he was younger to watch Les Rouge et Bleu, and playing there now, for the first time in his career, was always going to be very meaningful. Before this first leg, he would have dreamt of playing a key role in this clash. And he did, just as he did against Borussia Dortmund (an assist at home, a goal away) and Borussia Monchengladbach (scoring in the second leg of their round-of-16 tie). His performance on Wednesday, scoring the winner and being a constant threat, was one of his best since joining Manchester in 2018.

This year, the Algeria international has been one of City's key contributors, alongside Ilkay Gundogan, Ruben Dias, Phil Foden and De Bruyne. Of course, De Bruyne.

This was a special evening for the City captain. Until last weekend, there were doubts about whether he would be fit for this game. The ankle injury he suffered against Chelsea 10 days ago in the FA Cup semifinal loss put his participation in this first leg in jeopardy. For a while, he and Guardiola indicated they didn't think that he would be able to play. And after a pretty anonymous first half, De Bruyne stepped up after the break, even if, as he admitted himself, his goal was rather fortuitous.

"They are an unbelievable team with great players up front," he said after the match. "We pressed them differently after 30 minutes and we put them under more pressure. Then we played great in the second half, even if we are a bit lucky on our first goal. What changed in the second half was that we played more with the ball. It was too rushed in the first half. We tried to go forward too quickly, which is not our game. We tried to find space more patiently, and we did.

"We kept going after the first goal, but there is still a game to go, so we have to focus. We know we will suffer. We know how good they are. We know we have to work hard for the team at times, it will be the same in the second game."

Mahrez and De Bruyne led the way, City went for it, and their character and mental strength made the difference. They forced the Parisians into mistakes. Keylor Navas should have done better on De Bruyne's cross-turned-shot, and only Presnel Kimpembe and Leandro Paredes know what on earth they were doing in the wall on Mahrez's free-kick goal. Naturally, Guardiola was a happy man after the game.

"The second half was excellent in every department," he explained. "We need time to be more ourselves. In the first half, we didn't play free. In Dortmund, we conceded a goal first and then we came back, like tonight. I want us to be ourselves. We can only play in one way so we have to get it right."

If PSG lost their way and their focus, as we saw with Idrissa Gueye's red card, it is because Manchester City took the game away from them. In the second half, the hosts threw away everything they had worked so hard to create in the first. Marquinhos' goal made history as the centre-back became only the third player in history to score in the Champions League quarterfinals and semifinals two seasons in a row, after goal-scoring greats Cristiano Ronaldo and Antoine Griezmann. It was not enough on Wednesday. But there is still a second leg for PSG to turn things around.

"We have to believe and go there to play, score goals and win," PSG boss Mauricio Pochettino said after the game, ruing the "two accident goals" his team conceded. "It is difficult to accept. It is painful that it happens in a Champions League semifinal."

Travelling to Manchester has been happy hunting for PSG, having won their past two Champions League trips there, including earlier this season. Those results came in the red half of the city, though. Can they do the same on the blue side of town?