-LRB- CNN -RRB- -- Chelsea moved a step closer to breaking Manchester United 's stranglehold on the English Premier League title with a controversial 1-0 victory at home to Bolton Wanderers on Tuesday night . Nicolas Anelka headed the only goal against his former club just before halftime to put the London side four points clear of three-time defending champions United with four matches to play . Third-placed Arsenal can leapfrog United into second place with victory over London rivals Tottenham on Wednesday and be three points adrift of Chelsea . Bolton , just five points above the relegation zone , were angry after not being awarded a penalty in each half for alleged handball by Didier Drogba and John Terry -- but were lucky not to concede more goals as Chelsea dominated late in the match . `` They were n't claims for a penalty , '' Bolton boss Owen Coyle told match broadcaster ESPN . `` They were stonewall penalties . I knew it at the time . `` Didier Drogba is a world-class player , but looking at this replay he could be a world-class volleyball player . `` I 've asked the linesman about -LSB- the Terry incident -RSB- after the game but he 's said it hit his shoulder . He needs to take another look at that . '' Chelsea boss Carlo Ancelotti chose not to comment on the incidents . `` It is not my job to judge the work of the officials , '' the Italian said . `` It is a difficult job , sometimes they make the right decisions , sometimes they make bad decisions . `` We have to maintain this level . We are doing well , we are very focused and in a very good position , but we have a very difficult game on Saturday against Tottenham and we have to do our best to win that game . '' Chelsea were less impressive in the first half , and it took until the 43rd minute before France striker Anelka broke the deadlock with a close-range header from Drogba 's left-wing cross for his first goal since January . Bolton striker Kevin Davies had told reporters before the match that his former teammate Anelka was unhappy playing with Drogba , but the duo combined well to end Wanderers ' stubborn resistance . The recalled Salomon Kalou should have made it 2-0 in the 54th minute but goalkeeper Jussi Jaaskelainen blocked the Ivory Coast forward 's shot with his legs . Davies was booked for a crude tackle on Jon Obi Mikel in the 77th minute , and Frank Lampard hit the post soon after with a fierce low shot after a clever dummy by Kalou 's replacement Joe Cole . England midfielder Cole gave Chelsea fresh impetus , with Michael Ballack heading his cross tamely at Jaaskelainen . Terry drove a shot just wide from a corner but soon after was beaten in the air at the other end by Bolton substitute Johan Elmander -- however , the Swede 's header went wide . Cole should have doubled the lead in injury-time , but somehow stumbled over Yuri Zhirkov 's low cross when it seemed easier to score . Meanwhile , Inter Milan moved into the final of the Italian Cup with a 1-0 victory away to Fiorentina on Tuesday night , winning 2-0 on aggregate . Cameroon striker Samuel Eto'o scored the only goal in the 57th minute to keep Jose Mourinho 's team in the hunt for three trophies this season . The Champions League semifinalists , who drew 2-2 with Fiorentina at the weekend , will face either new Serie A leaders Roma or Udinese in the title match . Also on Tuesday , Cagliari sacked coach Massimiliano Allegri after the Sardinian team 's slump to 12th in the Italian top flight following a haul of just two points from nine matches . Allegri was voted Serie A coach of the year by his peers for guiding Cagliari to ninth place last season , but became the 16th to be dismissed this campaign .