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 it top Saturday. Manchester City's dismal 2-0 defeat at Stoke City in the early kickoff opened the door for pre-season relegation tips Leicester to reach the summit after 15 games and it responded in style 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 which 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 but drew a blank at the Liberty Stadium. Two goals inside the opening 15 minutes from Stoke's Marko Arnautovic, both created by Xherdan Shaqiri, condemned injury-hit City to defeat at a blustery Britannia Stadium. 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 its neighbor. The team was jeered off at Old Trafford after the fifth goalless stalemate in its last nine games. A late flurry of chances didn't disguise the problems United has up front under manager Louis van Gaal, who was missing captain Wayne Rooney to compound his shortage of strikers. West Ham — injury-hit and without a clean sheet in its previous nine games — struck the post twice in the first half and wasted great one-on-one chances through Victor Moses and Mauro Zarate. United dominated the final half-hour but couldn't find a way past goalkeeper Adrian, and dropped to fourth place in an increasingly tight title race. Fifth-placed Tottenham Hotspur drew for the eighth time of the campaign, 1-1 at West Bromwich Albion, after Dele Alli had given the visitors an early lead. Bottom club Aston Villa drew 1-1 at Southampton and fellow-struggler Norwich City lost 2-0 at Watford. — Agencies