Jamie Vardy's record scoring streak ended but Leicester City's improbable Premier League title challenge continued with Riyad Mahrez's hat-trick sealing a 3-0 win at Swansea City that put them top on Saturday.

Manchester City's dismal 2-0 defeat at Stoke City in the early kickoff opened the door for 2000-1 pre-season title shots Leicester to reach the summit after 15 games and they responded in emphatic fashion in south Wales.

Mahrez scored twice in the first 22 minutes and struck again after the break as Leicester moved on to 32 points, two clear of Arsenal who moved above Manchester City with a 3-1 home defeat of Sunderland -- Olivier Giroud scoring for both sides.

Vardy had scored for 11 consecutive Premier League matches and while he drew a blank at the Liberty Stadium, it had no effect on Claudio Ranieri's confident side who are still unbeaten away from home in the league this season.

Two goals inside the opening 15 minutes from Stoke's Austrian striker Marko Arnautovic, both created by influential Swiss playmaker Xherdan Shaqiri, condemned injury-hit City to defeat at a blustery Britannia Stadium.

"We can't accept how we played today," City keeper Joe Hart said. "It was a disappointing start and we could not recover from it."

Manchester United failed to take advantage of City's defeat, drawing 0-0 at home with West Ham United to stay fourth, level on 29 points with their neighbours.

There were some boos at fulltime after a fourth 0-0 draw in their last six home games.

"The most important thing is we are dominant and creating chances, but we have to improve because we don't score," United manager Louis van Gaal said.

Fifth-placed Tottenham Hotspur also missed the chance to capitalise as they drew 1-1 at West Bromwich Albion.