Diego Costa thrust himself back into the headlines with an 89th-minute winner as Chelsea edged West Ham United 2-1 in Antonio Conte's first Premier League game as manager last night.Eden Hazard, symbol of Chelsea's slump from champions to a 10th-place finish last season, opened the scoring at Stamford Bridge with a penalty early in the second half, before James Collins equalised in the 77th minute.Costa should have been shown a second yellow card after catching West Ham goalkeeper Adrian with a late challenge, but he stayed on to steer a winner into the bottom-left corner.The Spain striker's goal capped a positive night for Conte. But it was a bitter defeat for West Ham manager Slaven Bilic.With both managers spending the entire match on the edge of their technical areas, suited and gesturing animatedly, the game was characterised by hasty, imprecise football and tackling.The hosts' high defensive line prevented West Ham bringing lone striker Andy Carroll into the game. West Ham's resistance was broken two minutes into the second half after Cesar Azpilicueta charged down an attempted clearance by Michail Antonio.In seeking to atone for his error, Antonio succeeded in blundering into Azpilicueta from behind, obliging referee Anthony Taylor to point to the spot. Hazard thundered the penalty into the net.The hosts should have been reduced to 10 men when Costa, booked in the first half for dissent, caught Adrian with an ugly late challenge as the West Ham goalkeeper dallied over a clearance.West Ham looked to have pulled off a smash-and-grab with 13 minutes remaining when Collins hit a left-foot shot past Thibaut Courtois. But with full-time looming, former Marseille striker Michy Batshuayi flicked a long ball to Costa, who steadied himself before guiding a shot between Collins's legs and beyond Adrian's despairing drive...