Match ends, Crystal Palace 1, Watford 2.
Troy Deeney scored twice to steer Watford to victory and extend Crystal Palace's run without a league win to nine games.
The captain put Watford into an early lead from the penalty spot, but Emmanuel Adebayor's first goal for Palace drew the Eagles level.
Watford retook the lead with seven minutes left when Deeney drove home Ben Watson's cross.
And Palace ended with 10 men after Pape Souare was shown a red card late on.
The Senegalese defender was shown a straight red by referee Robert Madley for a two-footed challenge on Valon Behrami.
Watford's second league win of 2016 pushed them up into eighth place in the table, while Palace remain 12th.
Quique Sanchez Flores's side carved out their fifth Premier League win away from home this season, subduing their hosts with long spells of possession and incisive attacks.
In fact, Palace's equaliser came as a real shock, having failed to give Heurelho Gomes much to worry about in the first 44 minutes of the match.
After weathering an early spell of pressure from the Eagles in the second half, the Hornets gathered themselves and bided their time before striking when the chance presented itself late in the game.
Deeney finished smartly when the ball had arrived nicely for him off the head of a Palace defender, although his side went close to being drawn level again when Yohan Cabaye hit the post late on.
Tactical switch nearly pays off
Alan Pardew's half-time change, bringing on Lee Chung-yong for Connor Wickham, saw Wilfried Zaha move on to the left flank, and for a time it looked like the new approach could pay off.
Zaha had chances of his own and linked up with Adebayor to pose the Watford defence more problems early in the second half than they had had for the whole of the first.
But the threat faded as the second half wore on, and Palace must contemplate a slump in form that has seen them slip from fifth in the table just before Christmas to 12th as it stands.
Problems for Pardew?
Souare's sending off gives Alan Pardew more problems to wrestle with, ruling the defender out for the next three games.
The Eagles' last win came on 19 December at Stoke, but Adebayor's goal gives some cause for optimism.
The 31-year-old looked to be getting into the game more as it progressed, and he could provide his side with some much-needed goal threat - midfielder Yohan Cabaye and defender Scott Dann are Palace's joint-leading scorers with five each.
Man of the match - Troy Deeney
Crystal Palace boss Alan Pardew, speaking to MOTD: "It was a tough result for us. We couldn't get going in the first half.
On Watford penalty: "We have had situations where Scott Dann is dragged to the ground on regular occasions but nothing given, I am not going to say it was not holding, but to have it on the first corner at the first play was tough.
"We know we are on a tricky run and these things go against you on these runs. We just have to focus now and get out of this run. The league form is a bit of a worry and we just have to put it right.
"It is a 90 minute game and we wasted 45 minutes."
Watford boss Quique Sanchez Flores: "It is always important psychologically for players to win. You work hard every single week but you need to win to confirm the good feelings you have in the week.
"It is an important win for us, we are close to the target and we are happy with the performance of the players."
The stats you need to know
- Only Bournemouth (13) and Aston Villa (10) have taken fewer points at home this season than Crystal Palace (14).
- 52% of Palace's goals have come from set pieces, the highest proportion in the top flight.
- Troy Deeney has scored more goals from the penalty spot than any other Premier League player this season (five). Deeney also scored twice in a Premier League game for the first time.
- Referee Rob Madley has awarded a league-high 11 penalties in the 18 Premier League matches that he has taken charge of in 2015-16.
- Emmanuel Adebayor has scored his first Premier League goal in 475 days (October 2014 vs Newcastle).
- 22 of Emmanuel Adebayor's 97 Premier League goals have been scored from headers.
Palace face Spurs in the FA Cup next Sunday, but their next league action is not until 27 February when they visit the Hawthorns to play West Brom.
Watford have two home games in a row - against Leeds in the FA Cup fifth round on 20 February, and against Bournemouth in the league a week later.
- 23SouaréBooked at 90mins
- 22MutchSubstituted forCampbellat 73'minutes
- 21WickhamSubstituted forLeeat 45'minutes
- 29CapoueSubstituted forSuárezat 71'minutesBooked at 77mins
- 11N AmrabatSubstituted forAbdiat 62'minutes
- Robert Madley
- Shots on Target
Second Half ends, Crystal Palace 1, Watford 2.
Attempt missed. Joel Ward (Crystal Palace) header from the centre of the box is too high. Assisted by Wilfried Zaha with a cross.
Pape Souaré (Crystal Palace) is shown the red card.
Foul by Pape Souaré (Crystal Palace).
Valon Behrami (Watford) wins a free kick on the right wing.
Attempt missed. Damien Delaney (Crystal Palace) header from outside the box is high and wide to the right. Assisted by Lee Chung-yong with a cross.
Attempt blocked. Almen Abdi (Watford) right footed shot from outside the box is blocked. Assisted by Odion Ighalo.
Attempt missed. Wilfried Zaha (Crystal Palace) right footed shot from the left side of the box is too high following a corner.
Yohan Cabaye (Crystal Palace) hits the left post with a left footed shot from outside the box following a corner.
Corner, Crystal Palace. Conceded by Valon Behrami.
Foul by Lee Chung-yong (Crystal Palace).
Troy Deeney (Watford) wins a free kick in the defensive half.
Attempt blocked. Pape Souaré (Crystal Palace) left footed shot from outside the box is blocked. Assisted by Emmanuel Adebayor.
Offside, Crystal Palace. Lee Chung-yong tries a through ball, but Emmanuel Adebayor is caught offside.
Foul by Mile Jedinak (Crystal Palace).
Mario Suárez (Watford) wins a free kick in the defensive half.
Offside, Crystal Palace. Pape Souaré tries a through ball, but Emmanuel Adebayor is caught offside.
Goal! Crystal Palace 1, Watford 2. Troy Deeney (Watford) right footed shot from the centre of the box to the centre of the goal.
Corner, Watford. Conceded by Damien Delaney.