Andy Johnson inflicted more misery on a Watford side still reeling from their FA Cup exit with two goals in Crystal Palace's first win at Vicarage Road for 11 years.

The Hornets lost their third round replay at Chelsea 4-0 in midweek, and self-destructed against the Eagles by missing a succession of chances and having captain Neil Cox sent off for a professional foul.

Johnson made them pay by taking his tally to 17 goals for the season with an early header and a penalty, and Wayne Routledge's strike sandwiched in between gave Palace a three-goal half-time lead from which Watford never recovered.

Heidar Helguson did pull one back with a penalty of his own, but further goals from Julian Gray and Dougie Freedman left the Hornets casting nervous glances at the bottom three after just one win in their last nine league games.

Watford hit the crossbar through Paul Devlin after the Eagles had failed to clear an early corner, but the visitors were soon ahead through their top scorer in the ninth minute.

Johnson sent Gray sprinting away and his strong run ended in a cross which Ben Watson returned to the head of Neil Shipperley, with Johnson on hand to pounce on his knock-on and head home the move he had started.

Devlin, Cox and Scott Fitzgerald all missed gilt-edged chances to equalise before Hornets keeper Lenny Pidgeley pulled off a tremendous one-handed diving save in the 37th minute from Aki Riihilahti's diving header.

But he was beaten just two minutes later when Routledge capitalised on a fluffed clearance by Jack Smith to put the Eagles two goals up with a shot which ricocheted off Pidgeley's body.

Gavin Mahon and Cox both missed the target at the other end from close range before the Watford defender hauled down Johnson in the penalty area just before half-time and was promptly shown the red card by referee Howard Webb.

Palace's star man converted right-footed from the spot, but shortly after half-time Watford were handed a penalty of their own when Mark Hudson pushed over Fitzgerald and Helguson rolled home a nonchalant spot-kick to hand them a lifeline.

But the extra man eventually told when Gray waltzed past substitute Lloyd Doyley to fire home a fourth in the 73rd minute, and Freedman made sure by chipping Pidgeley to send the travelling fans home happy.

Teams

Watford: Pidgeley, Ardley, Cox, Gayle, Smith, Devlin, Mahon, Hand (Hyde 45), Cook (Doyley 45), Helguson, Fitzgerald (Dyer 81).

Subs Not Used: Chamberlain, Brown.

Sent Off: Cox (45).

Booked: Cook.

Goals: Helguson 58 pen.

Crystal Palace: Myhre, Butterfield, Hudson, Borrowdale, Granville, Routledge (Black 80), Riihilahti, Watson (Derry 68), Gray, Shipperley, Johnson (Freedman 75).

Subs Not Used: Berthelin, Soares.

Booked: Derry, Butterfield.

Goals: Johnson 9, Routledge 39, Johnson 45 pen, Gray 73, Freedman 90.

Att: 15,017

Ref: H Webb (S Yorkshire).