Central defenders Robert Huth and John Terry headed a goal in each half as Chelsea beat Birmingham City 2-0 on Sunday to reach the FA Cup fifth round.

Chelsea, playing after Bolton Wanderers won 1-0 at third division Oldham Athletic, reached Monday's draw with the polished football that has earned them a 10-point lead at the top of the English Premier League.

The win wrapped up a Cup weekend that went to form with comfortable wins for holders Manchester United [Images], Arsenal [Images], Everton and Newcastle United. The only slight surprise was Fulham's 1-1 draw at second division Derby County.

Terry was the key to Chelsea's victory, blocking Huth's marker Martin Taylor to allow the German a powerful free header when Damien Duff whipped over a sixth minute corner.

Though that block went unnoticed by the referee, there was no missing Terry's fine angled header in the 80th minute after a superb long ball from substitute Frank Lampard [Images].

The strike by Terry, whose brother Paul scored for fourth division Yeovil in their 3-2 Cup defeat at Charlton Athletic on Saturday, enabled manager Jose Mourinho to play out the rest of the game with 10 men -- by taking off the injured Huth.

Mourinho told Sky Sports News: "In the first half, I think we played very, very well...in the second we didn't, partly our fault and also because they improved a lot.

"But JT's goal killed the game and put us in the next round...and I think we deserved the victory."

Terry admitted agreeing a blocking manoeuvre with Huth, but said: "It's not something we work on the training ground."

City boss Steve Bruce saw the body check differently, saying: "We feel aggrieved because we know it's a training ground routine.

"We've all done it before, looking for the block, but you hope the referee spots it. But the two lads have done it extremely well and we fell for a sucker punch."

Chelsea, who have lined up a League Cup final with Liverpool on February 27, were deserving winners though at Stamford Bridge and had chances to win by a bigger margin.

DUFF SHOT

Duff was put clean through but skewed his shot wide of the target, while Huth's downward shot from another Duff corner reared up and clipped the bar just before the break.

Birmingham improved midway through the second half when Darren Anderton forced a good save from Carlo Cudicini and Robbie Blake fired narrowly wide, but Lampard was almost on the scoresheet at the other end with a neat first-time shot.

Bolton's Portuguese striker Ricardo Vaz Te headed their ninth minute winner at Oldham but the Premier League club were often under pressure and rode their luck in the second half.

"It was a professional performance from ourselves and a fantastic effort by Oldham," Bolton boss Sam Allardyce told the BBC. "It was a typical Cup tie at this level."

The win was marred, though, by an injury to Bolton defender Nicky Hunt, who was taken to hospital after a lunging tackle by Oldham striker Lee Croft.

Before the tie, Oldham boss Brian Talbot was involved in what police called a "minor incident" when his car was attacked near a disturbance at a Manchester polling station for the Iraqi elections.

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