Eden Hazard's penalty enabled Chelsea to preserve their four-point lead in the Premier League with a narrow 2-1 win at home to local rivals Queens Park Rangers on Saturday.
Diego Costa returned for Chelsea after four games out with hamstring trouble and he saw his side take a 32nd-minute lead when Cesc Fabregas teed up Oscar to bend in an exquisite shot with the outside of his right foot.
Charlie Austin equalised for QPR just after the hour when he beat Thibaut Courtois with a clever back-heel from Leroy Fer's cross-shot to claim his third goal in two games.
But Hazard gave Chelsea victory in the 75th minute when he calmly beat Rob Green from 12 yards after he had gone down under a challenge by Eduardo Vargas.
Hazard's goal enabled Jose Mourinho's side, who visit Maribor in the Champions League on Wednesday, to preserve their four-point advantage over second-place Southampton, who won 1-0 at Hull City.
Kenyan midfielder Victor Wanyama scored the game's only goal in the third minute at the KC Stadium, brilliantly lobbing Eldin Jakupovic from 40 yards after the Hull goalkeeper scuffed his clearance.
Arsenal climbed into the Champions League places after Alexis Sanchez scored twice in a 3-0 success at home to winless bottom club Burnley.
Defender Calum Chambers crossed for Sanchez to head Arsenal in front in the 70th minute and smashed home his first senior goal two minutes later after Tom Heaton parried a shot by Danny Welbeck.
Sanchez added a third in injury time from a Kieran Gibbs cross.
Arsene Wenger's side, who welcomed Theo Walcott back from a long-term knee injury, moved into fourth place at the expense of West Ham United, who came from two goals down to record a 2-2 draw at Stoke City.
Missing top scorer Diafra Sakho due to a shoulder injury, West Ham fell 2-0 behind through goals from Victor Moses and Mame Biram Diouf either side of half-time.
But Stewart Downing crossed for Enner Valencia to reduce the arrears on the hour and the Ecuador international returned the favour for Downing to drill home an equaliser with 17 minutes to play.
An Esteban Cambiasso own goal saw West Bromwich Albion win 1-0 at Leicester City, while Swansea City midfielder Jonjo Shelvey was sent off for two bookable offences as his side drew 0-0 at Everton.