LONDON: Jose Mourinho is still seething about what he perceives to be a campaign among referees to make life difficult for Chelsea in particular. But while the Blues continue to rip apart the opposition, as they did Swansea by 5-0, then the odd refereeing error here and there will prove irrelevant in the Premier League title race.

Diego Costa and Oscar inflicted most of the damage. Each scored two goals in the first half and Oscar’s creative play, in tandem with the composed Cesc Fabregas, was a delight.

He has overcome the early-season hangover which followed Brazil’s World Cup disaster and is again the equal of Manchester City’s David Silva in terms of creativity. Thus far Oscar has contributed to 13 of his club’s league goals – scoring six and assisting on seven – three more than he managed all of last term.

Costa, with 17 goals, has scored more times this season already than any Chelsea player managed in the entirety of the 2013-14 campaign. Chelsea could have scored more. Willian hit a post twice in the same first half.

Chelsea’s football was ruthlessly entertaining which is the ultimate ambition for any manager – to play well and win well. But the second factor is as important as ever. As Mourinho said: “Everybody wants to see us playing well and I’m the first. But if we play fantastically well and don’t win any trophies then nobody will remember this team in 20 years’ time.”

Mourinho’s men seized control after only 50 seconds when Oscar won the ball from Gylfi Sigurdsson and fired home from 25 yards. Sigurdsson almost atoned when he hit a post from long range but that was the closest Swansea came to a goal. The sale of Wilfried Bony appeared not only to have weakened their attack but weakened their morale.

Costa made it 2-0 after 20 minutes and a blunder by Federico Fernandez gifted the Spain striker his second goal just after the half-hour. Oscar put the Blues four-up two minutes later and Andre Schurrle, substiting for Willian, completed the scoring after the interval.

Petr Cech, retained in goal while Thibaut Courtois continues to nurse a finger injury, kept a third successive clean sheet in all competitions though he was fortunate early on when a shot from Sigurdsson hit a post. Not that it would have any ultimate difference against what Swansea manager Gary Monk hailed as a “strongest-ever” Chelsea side.