Chelsea boss Jose Mourinho described Diego Costa as a "special" player after the Spain striker fired the Blues two points clear in the Premier League.

Costa, who passed a late fitness test on a hamstring injury, scored a hat-trick as Chelsea beat Swansea 4-2.

The £32m summer signing from Atletico Madrid has seven goals in his first four games for the west London club.

"He is one of the best strikers at this moment in football," Mourinho told BBC Sport. "He is a special player."

Costa cancelled out John Terry's early own-goal with a header on the stroke of half-time and pounced twice after the break from close range to swing the match Chelsea's way.

He departed to a standing ovation from the home fans, who then watched Costa's replacement Loic Remy score his first goal for the club since joining for £10.5m from QPR.

"The team is an attacking team that creates a lot of chances and spaces for a striker," said Mourinho.

"The second goal is a brilliant collective action. [Cesc] Fabregas had a fantastic assist and Diego put the ball in the net. Diego is a good player but he is in a good team."

Costa's goals have added another dimension to a side that finished third in the league last season.

He has already scored two more league goals than Fernando Torres and Demba Ba each managed for Chelsea in the whole of last season, and only two fewer than Samuel Eto'o.

Former England striker Alan Shearer believes Costa's muscular forward play and finishing make him "tailor-made" for the Premier League.

"Everything impressed me about Diego Costa today," Shearer told BBC Radio 5 live. "He is looking the real deal. When it is not going as it should be for Chelsea, they have a goalscorer who can get them out of it."

And he added on Match of the Day: "When you consider it took Fernando Torres 43 games to get seven goals, Costa definitely makes a difference.

"What Chelsea have now is a guy that, when they are playing poorly, can score goals and pull them through. Chelsea did not play well against Swansea but just before half-time they got a corner and he scored.

"He is always available. He always wants the ball to feet and if you want to push him around and bully him it is alright because he will do the same to you.

"As well as goals, he can assist also. He can do pretty much everything. He has made a great start. He will get a bagful of goals this season if he stays fit because that team will create chances for him."

Former Blues winger Pat Nevin believes the only thing that can stop Costa scoring is injury.

"He looks like he will pick up a few injuries because he puts himself about, but he has got everything," the Scot said on BBC Radio 5 live.

"We knew he was strong and a natural finisher, but he has quick feet and a great knowledge of the game.

"He can play others in and is a complete centre-forward."