Diego Costa scored his fourth Premier League goal of the season . Dusan Tadic levelled the scoreline in the 19th minute from penalty spot . Nemanja Matic was penalised for foul on Southampton 's Sadio Mane . Chelsea XI : Courtois ; Ivanovic , Cahill , Terry , Azpilicueta ; Matic , Fabregas ; Willian , Oscar , Hazard ; Costa . Southampton XI : Forster ; Clyne , Fonte , Alderweireld , Bertrand ; Wanyama , Schneiderlin ; S. Davis , Tadic , Mane ; Long . Southampton claimed a point against Chelsea at St Mary 's in December .
Diego Costa scored his 18th Premier League goal of the season . Dusan Tadic levelled the scoreline in the 19th minute from penalty spot . Nemanja Matic was penalised for foul on Southampton 's Sadio Mane . Chelsea XI : Courtois ; Ivanovic , Cahill , Terry , Azpilicueta ; Matic , Fabregas ; Willian , Oscar , Hazard ; Costa . Southampton XI : Forster ; Clyne , Fonte , Alderweireld , Bertrand ; Wanyama , Schneiderlin ; S. Davis , Tadic , Mane ; Long . Southampton claimed a point against Chelsea at St Mary 's in December .