LONDON (AP):Demonstrating their efficient transformation under Antonio Conte, Chelsea’s players reeled off an 11th successive victory in a Premier League season for the first time yesterday.Diego Costa’s header secured a 1-0 win at struggling Crystal Palace, sending the leaders nine points clear of Liverpool and Arsenal.It came on the first anniversary of JosÈ Mourinho being fired, with the west London club a point above the relegation zone. Apparent harmony in the dressing room has replaced the “palpable discord” with the players which triggered Mourinho’s exit.Although the wins are racking up, Chelsea might soon pay for their inability to kill off games with the Palace success completing a hat-trick of 1-0 victories.The defence, though, is watertight under Conte, keeping nine clean sheets in the winning run that started after a 3-0 humbling at Arsenal and the switch to a three-man defence.”The manager must be a tailor and try and find the right fit for the team,” said Conte, the former Italy and Juventus coach. “For sure, for me, it wasn’t easy to arrive and understand very quickly the characteristics of my players. I needed a bit of time.”I tried a different solution before changing the formation, but I think the most important thing is the mentality, our strong mentality. Also hard work during the week tactical work, physical work, analysis.”With mist descending on the Selhurst Park field, the only goal in the lunch-time kick-off came from Chelsea’s first attempt on target in the 43rd minute.Costa rose above Scott Dann to meet CÈsar Azpilicueta’s cross and net his 13th goal of the season. The Spain forward has eclipsed last season’s haul for Chelsea before the halfway point has been reached.”If we’d arrived here today without the right concentration and focus, the will to fight and go into battle with your opponents, we’d have lost this game for sure,” Conte said. “Instead, we have great quality, but the players are putting that quality into the team.”COSTA OUTChelsea, though, will have to cope without Costa at home to Bournemouth on December 26. Chelsea’s top scorer picked up a fifth booking of the season for a tackle on Joe Ledley before scoring.Midfielder N’Golo KantÈ, who also accumulated five yellow cards with his second-half caution, also has two weeks off before the New Year’s Eve game against Stoke.Palace manager Alan Pardew might also have an enforced break unless results improve. Chelsea condemned Palace to an eighth loss in 10 games to leave the south London club three points above the relegation zone.”Chelsea are very sound defensively and didn’t really give us any chance to get at them as much as we’d have liked,” Pardew said. “They were confident in their defending, (with) good shape and discipline to their actions, and did enough offensively to edge it.”Chelsea equalled the 2009 team’s 11-match winning run set across two seasons in 2009.Arsenal’s 14-match winning run in 2002 remains a Premier League record – for now.