Bacary Sagna has hailed John Stones' character after the Manchester City defender scored a "vital" goal in a 5-3 Champions League success against Monaco.

England international Stones has been criticised for his defensive performances since moving from Everton, and he and the City back-line were again at fault as the Ligue 1 side led 2-1 and then 3-2 in the last-16 first leg.

With Sergio Aguero twice equalising, Stones' goal put City ahead before Leroy Sane gave the Premier League outfit a two-goal advantage going into the return leg in France.

And Sagna was keen to praise his defensive colleague, insisting that he had a good game and will continue to improve.

"[Stones] has been criticised in the past weeks, but he's a great defender and he showed character," Sagna told CityTV.

"He is always working hard to get into the team and to help the team, and he did that because his goal was vital. He came back into the game, showed some character and had a good game.

"Even if we conceded some goals, he had a good game. He is going to improve. He's still young, he will improve and he is already a top player."

Sagna acknowledged his disappointment to concede three goals at home, but he was pleased with a "crazy" win.

"It was just a crazy game," he said. "Of course, we are happy because we won and we came back from a difficult situation.

"But, as a defender, I am always a bit sad when we concede goals - that's the only bad point. We can be happy, because we showed some character tonight, we showed that we want to qualify.

"It was not easy because [Monaco] are a quality team. They are on top of the league and there is a reason why they are. They have good players and managed to create some chances.

"We defended as a team and kept working hard as a team, so we have to think positive and we have a second leg to play."