If Chelsea’s Diego Costa and Oscar were trying to send Manchester City a message, they likely heard it loud and clear during Saturday’s 5-0 smashing of Swansea City at Liberty Stadium.

Powered by Costa and Oscar’s first half braces, Chelsea controlled the match wire-to-wire and more victories like this will certainly increase pressure on second-place Manchester City.

The Blues improved their first-place lead to five points ahead of City’s critical matchup Sunday with Arsenal at the Etihad. And after a string of Capital One Cup and FA Cup matches, Chelsea and City will square off on Jan. 31 at Stamford Bridge.

Moments after the opening whistle, Oscar set the tone with his goal in the first minute of action and connected his brace in the 36th, bookending Costa’s two goals in the 20th and 34th minutes. The Spanish star’s first year with Chelsea continues to be a roaring success, as he remains the league’s top goal scorer with 17.

Coming on for Willian in the 76th, Andre Schurrle strengthened Chelsea’s lead and goal differential in league play with his goal in the 79th off an assist from defender Branislav Ivanovic.

Swansea was plagued by poor ball control and decision-making throughout the first half, starting with Oscar 50 seconds into the match.

The Brazilian deftly intercepted midfielder Gylfi Sigurdsson’s pass and coasted to the top of the box for a stellar right-footed strike to the bottom left corner.

Costa would double the lead after Cesc Fabregas, Willian and Oscar weaved around the Swansea back line to spring him clear in front of the net for a right-footed shot and goal.

Already down 2-0, Swansea appeared rattled and unsure how to break down the Chelsea defense, an insecurity that led to defender Federico Fernandez mistakenly sailing his back pass straight to Costa in the penalty area for a another quick shot and score in the 34th.

Two minutes later Willian charged through Swansea’s midfield and fired a through ball to Costa, who would notch his second assist of the season by helping Oscar connect this brace with a powerful strike in the 36th.