Gianfranco Zola made a winning start as Watford manager as two late goals sealed victory at Crystal Palace.
Owen Garvan had put Palace ahead with a 13th-minute penalty, before Martin Taylor tapped home an equaliser.
Palace regained the lead when Garvan lashed a shot beyond former Arsenal goalkeeper Manuel Almunia.
However, Almen Abdi levelled with a 25-yard effort before fellow new signing Matej Vydra struck from outside the box to snatch victory.
Zola, back in management since he was sacked by West Ham two years ago, will have been happy with his side's start as they fashioned the first two chances of the game, Joe Garner heading wide before Julian Speroni saved Abdi's shot.
Watford's match winner
Matej Vydra is a 20-year-old Czech striker who has been with Udinese since 2010. He previously played for Czech side FC Baník Ostrava and has also had a loan spell at Belgian outfit Club Brugge.
However, it was Palace who took the lead when Wilfried Zaha was brought down inside the area by John Eustace and Garvan coolly converted.
Watford were level less than 10 minutes later as Speroni failed to hold Sean Murray's effort and the ball fell to Taylor, who made no mistake.
But Palace restored the lead in the 29th minute as Speroni's goal-kick was flicked onto Garvan, who controlled the ball before firing beyond Almunia.
The home side had chances to add to their advantage after that, but were made to pay for their profligacy as Abdi - on loan from Italian side Udinese - equalised with a superb long-range strike with two minutes remaining.
Fellow Udinese loanee Vydra then grabbed the winner with virtually the last kick of the game with a shot from outside the box.
Watford manager Gianfranco Zola:
"Matej Vydra is a player who has the qualities to make a good impression on this team. He is going to get better and better because he is still learning.
"The type of football we need to play is expansive so the players need to be in top condition. Give me time. I'm learning a lot from my players and learning a lot from this division.
"How far we can go is difficult to say, but we will give it [promotion] a go."
Crystal Palace manager Dougie Freedman:
"The last 10 minutes were obviously disappointing.
"I don't think we did enough to win the game but I thought we had done enough to get a draw. We just couldn't defend as a whole team in the end to come away with the points.
"A couple of our players will need time to settle in but as a defensive unit we have to be better than that to win games. We didn't focus on our jobs as well as we should have. There are no excuses and we will move on quickly."
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Live Text Commentary
Full Time The game is over, as the referee blows his whistle.90:00 +3:37
Assist on the goal came from Carl Dickinson.90:00 +3:37 Goal scored
Goal! - Matej Vydra - C Palace 2 - 3 Watford Matej Vydra finds the net with a goal from the edge of the area to the top right corner of the goal. Crystal Palace 2-3 Watford.90:00 +3:28 Booking
Booking Matej Vydra booked.90:00 +1:24
Aaron Wilbraham gives away a free kick for an unfair challenge on Mark Yeates. Carl Dickinson restarts play with the free kick.89:49
Almen Abdi takes a shot. Save made by Julian Speroni.87:51 Goal scored
Goal! - Almen Abdi - C Palace 2 - 2 Watford Almen Abdi finds the net with a goal from outside the area to the bottom left corner of the goal. Crystal Palace 2-2 Watford.82:34
Connor Smith is penalised for handball and concedes a free kick. Direct free kick taken by Mile Jedinak.82:06
Free kick awarded for an unfair challenge on Joel Ward by Connor Smith. David Wright takes the free kick.81:28
Free kick taken by Wilfried Zaha.81:28 Booking
Booking Carl Dickinson receives a caution.81:15
Unfair challenge on Wilfried Zaha by Carl Dickinson results in a free kick.78:27 Substitution
Substitution Connor Smith comes on in place of Sean Murray.78:27 Substitution
Substitution Chris Iwelumo comes on in place of Joe Garner.77:29
Inswinging corner taken left-footed by Owen Garvan, Mile Jedinak has a headed effort from close range and clears the crossbar.76:19
Foul by Almen Abdi on Mile Jedinak, free kick awarded. Free kick taken by Julian Speroni.71:41 Substitution
Substitution David Wright replaces Jonathan Parr.71:25
Shot from outside the area by Carl Dickinson misses to the left of the goal.70:46
Inswinging corner taken right-footed by Sean Murray from the left by-line, Mile Jedinak makes a clearance.69:41
Jonathan Hogg gives away a free kick for an unfair challenge on Wilfried Zaha. Owen Garvan restarts play with the free kick.
Mile Jedinak challenges Carl Dickinson unfairly and gives away a free kick. Sean Murray delivers the ball from the free kick right-footed from left channel, save made by Julian Speroni.65:11
Shot by Sean Murray from outside the box goes high over the target.62:48
Lloyd Doyley challenges Jonathan Parr unfairly and gives away a free kick. Free kick taken by Owen Garvan.62:11
Joe Garner is penalised for a handball. Free kick taken by Jonathan Parr.59:15
Inswinging corner taken by Sean Murray, clearance made by Aaron Martin.58:23 Substitution
Substitution John Eustace leaves the field to be replaced by Matej Vydra.57:21
Free kick awarded for a foul by Jonathan Parr on Mark Yeates. Free kick taken by Carl Dickinson, Shot from deep inside the area by John Eustace clears the bar.55:42
Free kick awarded for an unfair challenge on Sean Murray by Jonathan Parr. Free kick taken by Martin Taylor.50:51
Kagisho Dikgacoi concedes a free kick for a foul on Sean Murray. Free kick taken by Mark Yeates.45:01
The referee starts the second half.45:00 +2:10 Half time
Half Time The ref blows to end the first period.37:24
Free kick awarded for a foul by Joe Garner on Aaron Martin. Julian Speroni takes the free kick.36:27
Mark Yeates has an effort at goal from just outside the box which goes wide of the left-hand post.33:01
Inswinging corner taken left-footed by Owen Garvan from the right by-line, Kagisho Dikgacoi takes a shot. Martin Taylor manages to make a clearance.32:28
Short corner worked by Wilfried Zaha.28:55 Goal scored
Goal! - Owen Garvan - C Palace 2 - 1 Watford Owen Garvan gets on the score sheet with a goal from close range to the bottom right corner of the goal. Crystal Palace 2-1 Watford.27:54
Headed effort from close range by Joe Garner goes wide left of the goal.26:29
Foul by Jonathan Parr on Lloyd Doyley, free kick awarded. Free kick taken by Nyron Nosworthy.21:55 Goal scored
Goal! - Martin Taylor - C Palace 1 - 1 Watford Martin Taylor finds the back of the net with a goal from close range low into the middle of the goal. Crystal Palace 1-1 Watford.21:32
Inswinging corner taken left-footed by Carl Dickinson from the right by-line.21:14
Effort from outside the box by Mark Yeates goes wide right of the target.19:43
Joe Garner produces a header from inside the area that goes over the crossbar.19:19
Short corner taken by Carl Dickinson.18:28
Unfair challenge on Mark Yeates by Joel Ward results in a free kick. Mark Yeates crosses the ball from the free kick right-footed from left channel, clearance by Joel Ward.16:58
Free kick awarded for an unfair challenge on Joe Garner by Aaron Martin. Mark Yeates restarts play with the free kick.14:53
The offside flag is raised against Joe Garner. Direct free kick taken by Julian Speroni.14:17
Dean Moxey challenges Lloyd Doyley unfairly and gives away a free kick. Free kick taken by Manuel Almunia.13:23
Free kick awarded for a foul by Lloyd Doyley on Jonathan Parr. Owen Garvan crosses the ball in from the free kick.12:38 Goal scored
Goal! - Owen Garvan - C Palace 1 - 0 Watford Placed penalty scored by Owen Garvan. Crystal Palace 1-0 Watford.11:34
John Eustace gives away a Penalty for an unfair challenge on Wilfried Zaha.11:25
Outswinging corner taken from the left by-line by Owen Garvan.8:43
Wilfried Zaha has an effort at goal from outside the area missing to the wide right of the goal.7:37
Lloyd Doyley fouled by Wilfried Zaha, the ref awards a free kick. The free kick is swung in left-footed by Carl Dickinson.5:33
Almen Abdi takes a shot. Save by Julian Speroni.3:22
Headed effort from close range by Joe Garner goes wide left of the target.0:00
The match gets underway.
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