Chelsea’s Lampard takes a free-kick against Norwich, at Stamford Bridge, on Saturday. (AFP)

London: Chelsea striker Didier Drogba was knocked unconscious during Saturday’s 3-1 win over Norwich City but is being released from hospital after checks.

“Chelsea Football Club can confirm Didier Drogba will be released from hospital tonight following medical tests,” a club statement said.       

“The striker ... is suffering from mild concussion. The club’s medical staff will continue to monitor the 33-year-old over the coming days.”

The Ivorian was drafted 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 midway through the second half.

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

He did not move initially as medics attended to him and was then carried off on a stretcher before being taken to hospital. The game contained 11 minutes of stoppage time. “The incident looks pretty nasty from the bench,” Chelsea coach Andre Villas-Boas said.

“It’s a natural physical contact and can happen, but we have to praise the immediate response from the players on the pitch to call the bench for a dangerous situation.”

Talking about the match, Juan Mata scored on his debut for a still-stuttering Chelsea.

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.

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.

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.

Hapless Blackburn Rovers lost 0-1 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.

Later on Saturday, new signings Jordan Henderson and Charlie Adam scored their first Liverpool goals in a 3-1 victory over Bolton. Henderson, who joined from Sunderland, struck in the 15th minute at Anfield after Jussi Jaaskelainen parried a volley from Stewart Downing.

Former Blackpool midfielder Adam whipped in the corner that Martin Skrtel headed home in the 52nd. And Adam got on the scoresheet a minute later when he finished off good work from Dirk Kuyt by firing low past Jaaskelainen.