Leroy Sane insists Manchester City have room for improvement despite Saturday's comprehensive 4-0 win at West Ham.

The Premier League champions extended the unbeaten start to their title defence to 13 matches as Germany winger Sane hit a brace, following early strikes from David Silva and Raheem Sterling.

West Ham, under former City boss Manuel Pellegrini, posed questions of their opponents throughout and Sane felt Pep Guardiola's side should not have made such heavy work of their eighth league clean sheet this season.

"We played a really good game going forward, also defensively," said Sane.

"But we gave the opponent too many chances to put us under pressure. They were really confident and kept going even when we were winning 3-0.

"It's always difficult after the international break, when everyone is coming back together after 10 days playing for their national teams. But, overall, really good."

Sane now has five Premier League goals this season and has scored on each of his past three top-flight starts.

"I always try to give my best for the team," he said. "The manger is putting me in the starting eleven. It's good to have his confidence."

Michail Antonio hit the post for West Ham before the hour and felt it could have been a different story had he and Marko Arnautovic made the most of first-half opportunities.

"We had quite a few chances – me, Marko – but it's just one of these things where it wasn't our day," he said.

"I don’t think the score showed the way we played. I think they had four good opportunities and they've taken their chances."

On the Premier League title race, Antonio added: "I definitely feel they're one of the best teams in the league. Them and Liverpool are running away with it and Chelsea have picked up form."