Chelsea cemented their position on top of the Premier League with a 3-1 victory at title rivals Manchester City, while Alexis Sanchez's hat-trick in a 5-1 thrashing of West Ham took Arsenal into second place on Saturday.

Gary Cahill's own goal from a Jesus Navas cross gifted City the lead on the stroke of half-time, but Diego Costa equalised with a clinical finish in the 60th minute.

Costa capped a dominant display by setting up substitute Willian for Chelsea's second goal in the 70th minute before Eden Hazard struck to send Antonio Conte's men four points clear of City at the top.

City's frustration boiled over in stoppage time with red cards for Sergio Aguero and Fernandinho, the former for an ugly lunge on David Luiz, the latter for pushing Cesc Fabregas over an advertising board.

"It was very tough and the game was open until the end. There were lots of chances for both teams to score," Conte said.

"I saw lots of character from my team and that's very important to grow. But we must continue to work and improve."

City striker Aguero faces a four-match ban and boss Pep Guardiola said: "It's a pity it finished like this. I don't like that. I apologise for what happened."

Chelsea's eighth successive league victory condemned Guardiola to a first defeat at Eastlands, where his side have now gone four home games without a win.

City were left to rue some profligate finishing as Kevin de Bruyne hit the crossbar from close-range before Chelsea's equaliser.

While City spluttered, Arsenal stepped up their title challenge with a ruthless performance that kept them within three points of Chelsea.

Arsene Wenger's side struck in the 24th minute when Angelo Ogbonna was caught in possession and Alexis Sanchez seized on the loose ball to set up Mesut Ozil, who tapped into the empty net.

Chile forward Sanchez got the second in the 72nd minute with a clinical finish and netted again eight minutes later.

West Ham substitute Andy Carroll struck in the 81st minute, only for Alex Oxlade-Chamberlain to smash in Arsenal's fourth moments later.

Sanchez completed his treble with a deft 86th-minute effort as Arsenal extended their unbeaten league run to 13 matches.

"Sanchez can always give you something special. He's a fighter and a classy player. You don't find many like him," Wenger said.

"I believe we are on a strong run and it's down to us to be mentally ready to maintain that run."

- Pardew relieved -
Sunderland climbed off the bottom with a 2-1 win over Leicester.

David Moyes' side took the lead in the 64th minute when Leicester defender Robert Huth deflected a Jan Kirchhoff header into his own net.

Jermain Defoe grabbed Sunderland's second goal in the 77th minute and although Japan striker Shinji Okazaki reduced the deficit three minutes later, the hosts held on for a third win in their last four league games.

Struggling champions Leicester remain just two points above the relegation zone after a fifth successive league game without a win.

Harry Kane's double and a brilliant strike from Son Heung-Min inspired Tottenham as they got back on track with a 5-0 demolition of Swansea.

Mauricio Pochettino's fifth-placed team suffered their first league defeat of the season at Chelsea last weekend, but they won for just the second time in their last seven league games after opening the scoring in the 39th minute.

England forward Kane drilled in the penalty after Kyle Naughton was harshly ruled to have fouled Dele Alli.

A superb volley from Son doubled Tottenham's lead just before half-time and ended the South Korean's 10-match goal drought.

Kane struck again four minutes after the interval and Christian Eriksen claimed Tottenham's final two goals in the 70th and 90th minutes to leave Swansea bottom of the table.

Crystal Palace striker Christian Benteke eased the pressure on boss Alan Pardew with a brace in a 3-0 win over Southampton at Selhurst Park.

After six successive defeats, including an astonishing late meltdown in a 5-4 loss at Swansea last weekend, Pardew finally got a lucky break when Palace went ahead in the 33rd minute.

Southampton keeper Fraser Forster miskicked Jose Fonte's backpass to gift the simplest of tap-ins to former Liverpool forward Benteke.

James Tomkins netted for Palace in the 36th minute and Benteke marked his 26th birthday with his second goal in the 85th minute.

Stoke eased to a 2-0 win against Burnley, while West Bromwich Albion beat Watford 3-1.