Hazard's best return - the match stats
- Costa's first strike was his 50th in the Premier League in his 85th game - only seven strikers have reached the milestone faster.
- Hazard has scored 15 league goals this season - his best return in a single campaign in the competition.
- Since their return to the top-flight in 2012-13, Southampton have scored more away Premier League goals at Stamford Bridge than any other side (nine).
- Fabregas' assist for Costa's goal was his 103rd in the Premier League - second only to Manchester United legend Ryan Giggs (162).
- Cahill has scored 26 Premier League goals - excluding penalties - the second most of any defender in the competition (after team-mate John Terry with 40).
- Saints conceded four goals in a Premier League away game for the first time since 5 April 2014, when they lost 4-1 at eventual champions Manchester City.
- The Blues have now failed to keep a clean sheet in their past 11 Premier League games.