Israeli coach Avram Grant has signed a four-year contract extension with Chelsea, the Premiership side announced on their website on Thursday. The 52-year-old, who took over following Jose Mourinho's departure in September, has been rewarded for Chelsea's impressive results. Despite Chelsea's defeat to Manchester United in Grant's debut, the Blues have gone 16 matches unbeaten in all competitions afterwards. Chelsea lie third in the Premiership, just three points behind leaders Arsenal, whom they face in a crucial clash on Sunday. The three-time English champions have also topped their group in the UEFA Champions League to reach the knock-out phase.