Adrian Mutu rediscovered his goalscoring touch, hitting a brace as Chelsea dismissed Watford from the FA Cup 4-0 at Stamford Bridge.
This third round replay that followed a 2-2 draw at Vicarage Road was all but over after six minutes when the Romanian hit his first in somewhat controversial fashion.
A Frank Lampard left-footer from 25 yards was parried out by on-loan goalkeeper Lenny Pidgeley.
Under pressure from Jimmy Floyd Hasselbaink, Neal Ardley miscued a clearance back into play where Mutu tucked the ball home with a deft right-footer from six yards.
Assistant referee Bernard Baker signalled that Mutu was offside and referee Alan Wiley agreed. An Irate Mutu raced to Baker to argue the ball he received had come off Ardley.
After Baker and Wiley conferred, the referee gave the goal.
Justice was done in that Chelsea were the victims of a goal that wasn't in the first match.
Watford could feel themselves slightly aggrieved as they forced four corners in the first four minutes, but failed to capitalise on their early pressure.
A Jaime Hand effort on 30 minutes was their first chance from open play.
Four minutes after that and Hasselbaink made it 2-0.
A delightful through ball by William Gallas found Hasselbaink running into the Watford area, on the right. He took one touch before arrowing a low right-foot drive across Pidgeley and into the far corner of the net.
It took the West Londoners until 76 minutes before they hit their third and a wonderful goal it was.
A Joe Cole pass was collected from over his head by Mutu, who, in one swift movement, turned and unleashed a crisp curving drive from just inside the area, giving the keeper no chance.
Pidgeley was sick of the sight of the Chelsea forwards and substitute Eidur Gudjohnsen produced an fantastic goal six minutes from time.
A quick break by Chelsea saw Lampard pass to Cole, to Damien Duff who passed to Gudjohnsen, who caressed a beautiful right-footer high and wide of Pidgeley.
Watford boss Ray Lewington confirmed that Chelsea were worthy winners: "The first goal was vital - we dreaded that.
"We can't complain about the first goal as we had a huge slice of luck in the first game." Chelsea will play Scarborough away in the fourth round, having lost 2-3 to the Seadogs in the League Cup in 1989.
Coach Claudio Ranieri said: "I've never been to Scarborough, but I believe it's got a good beach. Lampard and Terry will love it, I prefer something hotter, but we will expect a big battle."