Chelsea extended their lead over Manchester City at the top of the Premier League to five points after slotting five goals past Swansea.
Chelsea’s five point lead remains, at least, until the end of today’s fixture between Arsenal and Man City when the Manchester based team could cut the lead with a win or draw against Arsenal.
Swansea, who stay in ninth place, are now winless in the four league games played this year.
Chelsea quickly opened the scoring with midfielder Oscar pouncing on a wayward pass by Swansea’s Gylfi Sigurdsson to fire a 20-yard shot past Lukasz Fabianski within 50 seconds of kicking off.
Sigurdsson nearly made amends straight away when his rasping shot from the edge of the area struck Petr Cech’s right-hand post.
The visitors were, however, full of confidence and took a stranglehold in midfield, as Oscar, Costa and Willian found plenty of space behind Swansea’s midfield.
Costa, who scored a hat-trick in September’s reverse fixture, rounded off a wonderful team move after 20 minutes, collecting Cesc Fabregas’s cute pass to fire past Fabianski from inside the penalty area.
Things soon got worse for Monk’s side as defender Federico Fernandez gifted Costa his second on the half-hour mark.
The Argentine’s attempted back-pass to Fabianski was picked off by the Spanish striker, who calmly slotted the ball past the Polish goalkeeper.
Chelsea’s fifth goal came with a fine team goal when substitute Schurrle tapped home from Branislav Ivanovic’s cut-back.
Swansea, who did not have a shot on target in the whole game, are now without a league win since the Boxing Day victory against Aston Villa.