Comment on Chelsea pull away, Toure rescues Man City

London (AFP) - Diego Costa scored again as Chelsea established a seven-point lead at the Premier League summit on Saturday by comfortably beating 10-man West Bromwich Albion 2-0 at Stamford Bridge.Costa opened the scoring in the 11th minute, leaping into the air to control Oscar's left-wing cross on his chest and then slamming a side-foot volley past Ben Foster for his 11th goal of the campaign.Eden Hazard added a second in the 25th minute, smuggling a deflected shot beneath Foster from Cesc Fabregas's corner, before West Brom's Claudio Yacob was sent off for a two-footed challenge on Costa.Victory saw Chelsea set a new club record of 12 unbeaten games from the start of the season.Jose Mourinho's side are now seven points clear of second-place Southampton, who visit Aston Villa on Monday, and remain eight points above defending champions Manchester City, who won 2-1 at home to Swansea City.Despite having captain Vincent Kompany back from injury, Manchester City fell behind in the ninth minute at the Etihad Stadium when Wilfried Bony finished calmly from Nathan Dyer's lofted through-ball.But Stefan Jovetic swept home Jesus Navas's low cross to equalise 10 minutes later and Yaya Toure gave the hosts victory early in the second half after a characteristic burst into the area.It was only City's second win in seven games.