Juan Mata scored on his debut for a still-stuttering Chelsea in a 3-1 home win over promoted Norwich City as the Londoners joined Wolverhampton Wanderers at the top of the Premier League on Saturday.

Andre-Villas Boas's new side have failed to sparkle in the early weeks of the Premier League season but Portuguese full back Jose Bosingwa gave Chelsea a superb early start with a rare goal from 22 metres.

Norwich equalised in comical fashion when stand-in goalkeeper Hilario bungled a cross and Grant Holt hooked into an empty net midway through the second half but the hosts went ahead again through Frank Lampard's 82nd-minute spotkick.

The penalty was awarded when Norwich goalkeeper John Ruddy was dismissed for bringing down Ramires and Spanish substitute Mata exposed Norwich's 10 men when he bent in a third goal in injury time.

Chelsea striker Didier Drogba was drafted back into the starting lineup to partner Fernando Torres up front but was accidentally punched as Norwich goalkeeper John Ruddy came out to meet the ball.

Droga was already unconscious from the punch and hit the ground awkwardly.

He did not move initially as medics attended to him but he then started to flex his arms before being stretchered off. The game ended up having 11 minutes of stoppage time.

"He will have a full exam. He was completely unconscious," the Portuguese coach said.

"The doctor did a great job. He is showing progressive signs of recovery. We hope for his wellbeing as a person first," he added.

Argentine Franco Di Santo scored twice to give Wigan Athletic a 2-0 home win over promoted Queen's Park Rangers with the visitors deciding not to give Joey Barton a debut after his move from Newcastle United.

Villa and Wigan are joint fifth.

Wolves had won their opening two fixtures, like Manchester City and Manchester United, but were content to leave Aston Villa with a 0-0 draw after the Birmingham-based side put their local rivals under the cosh for long spells.

Gabriel Agbonlahor had arguably the best chance for the hosts but goalkeeper Wayne Hennessey pulled off a good save.

Hapless Blackburn Rovers lost 1-0 at home to Everton after Junior Hoilett and Mauro Formica both missed penalties for the home side before Mikel Arteta made no mistake with his injury-time spotkick.

Promoted Swansea City, still looking for their first Premier League goal, drew 0-0 at home to Sunderland in a game where both sides hit the bar.

Jordan Henderson and Charlie Adam netted their first Liverpool goals in another 3-1 triumph over Bolton Wanderers on Saturday.

Liverpool took the lead after 15 minutes against Bolton when former Sunderland midfielder Henderson sent Anfield into raptures with a coolly-taken strike following superb play by Luis Suarez, preferred up front to Andy Carroll.

The Uruguayan's chip on to the bar later on was perhaps overly ambitious but Liverpool's win was never in doubt once Martin Skrtel headed in Adam's corner before the former Blackpool midfielder drove home a crisp right-footed shot.

Ivan Klasnic netted a late consolation.