London: Juan Mata scored on his Chelsea debut to complete a 3-1 victory over Norwich in the Premier League on Saturday after teammate Didier Drogba was knocked unconscious.
The new recruit from Valencia netted in the 11th minute of stoppage time, which resulted from Drogba requiring treatment on the pitch after being accidentally punched by Norwich goalkeeper John Ruddy.
"He was completely unconscious," Chelsea manager Andre Villas-Boas told the BBC. "The doctor did a great job. He is showing progressive signs of recovery but we need a full exam which is being done."
Frank Lampard restored Chelsea's lead from the penalty spot after Grant Holt canceled out Jose Bosingwa's early opener.
Also Saturday, Franco Di Santo scored twice as Wigan beat Queens Park Rangers 2-0 and Mikel Arteta's penalty gave Everton a 1-0 win at Blackburn.
But there were scoreless draws between Aston Villa and Wolverhampton Wanderers, and Swansea and Sunderland.
At Stamford Bridge, Chelsea got off to the perfect start when Bosingwa scored his first goal since November 2008.
Just six minutes had elapsed when the Portugal defender found the back of the net from 25 meters (yards) via the inside of the post.
Norwich, though, was back in the game in the 63rd after Chelsea goalkeeper Hilario needlessly came racing off his line to claim a cross and collided with Branislav Ivanovic, allowing Holt to hook the ball into the empty net.
It got worse for the hosts as they tried to regain the lead, with Drogba knocked unconscious after an aerial challenge with Ruddy.
Doctors raced onto the pitch to treat the 33-year-old striker, with the game stopped for seven minutes while he was loaded onto a stretcher and carried off wearing a breathing aid.
The game turned back in the Blues' favour when a breakaway by Chelsea brought a penalty scored by Lampard.
At Ewood Park, Blackburn had two attempts to net from the spot and missed both.
Junior Hoilett saw his penalty saved by Tim Howard at the start of the second half before Mauro Formica shot against the post.
Arteta then showed Blackburn how it was done, clinching Everton's win with a penalty kick after Christopher Samba climbed on the back of Marouane Fellaini.
Everton celebrated its first win of the season while Blackburn is stranded on zero points after three games.
Swansea has two points but is yet to score since being promoted, drawing against a Sunderland side also searching for its first win.