Match ends, Watford 2, Everton 3.
Theo Walcott struck an injury-time winner as 10-man Everton came back from two goals down to stun Watford in a topsy-turvy encounter at Vicarage Road.
Carlo Ancelotti's players raced to their jubilant supporters after Walcott applied the finishing touch to a counter-attack as Watford pressed for the winner.
After Adam Masina drove the home side ahead and Roberto Pereyra coolly added a second, Everton looked fully out of sorts, before two goals arrived in first-half added time from central defender Yerry Mina.
Fabian Delph's dismissal for two yellow cards in 13 second-half minutes looked set to temper the away side's comeback, only for Walcott to nudge home in the 90th minute and move the Toffees to ninth in the table, their highest position since September.
A win would have lifted the hosts out of the Premier League relegation zone but instead they are 19th with 23 points.
"It hurts. Disappointing is an understatement", reflected Watford boss Nigel Pearson.
Everton joy from vulnerable positions
Walcott declared himself "shattered" in the immediate aftermath but stressed his side have "ambitions to go up higher" in the table.
The striker's first goal of the season helped Everton break their run of being winless in 35 outings when they have conceded the opening goal.
The Merseyside club had lost their last 25 away games in a row when two or more goals behind.
So the fact they found a way to win this fixture points to a steeliness that seems to have arrived since Ancelotti took charge.
The Toffees have now lost just once in seven league games - against champions Manchester City - under the Italian.
"This is football, it's unpredictable," said Ancelotti, who had seen his side throw away a 2-0 lead in injury time to draw 2-2 with Newcastle in their previous league outing.
Everton were abject for 45 minutes as Watford eased ahead - Delph squandering possession for Pereyra to double the advantage.
But Mina's goals in the 46th and 49th minutes of the opening period transformed the contest. The Colombian finished from six inches out before heading in the leveller.
The visitors carried momentum into the second period without creating anything clear cut, but when Delph saw red for missed tackles on Pereyra and Etienne Capoue, Everton again looked hugely vulnerable.
But they limited the Hornets and when former Watford player Richarlison raced away to slip in Moise Kean, his miss-hit finish fell fortunately for Walcott to seal a win that had looked so unlikely earlier in the afternoon.
Watford tune out at key moments (again)
Ancelotti said his side "didn't deserve to equalise" before half-time and the stunned faces of some Watford fans at the final whistle pointed to an outcome few had seen coming.
Pearson was quick to highlight the way his side failed to "manage" the closing minutes of the first half and the result may sting a little more given they surrendered the lead and conceded an injury-time winner in their previous league outing at Aston Villa.
Had they held on to a point in each of the fixtures they would now sit above the bottom three on goal difference.
But while this will hurt, there is plenty to offer encouragement in their fight against the drop. For 45 minutes they appeared well organised and forced Everton's attacking players to feed off scraps or attempt crosses from deep positions.
At the other end, Gerard Deulofeu showed class and craft in teeing up Masina for the opener, while Pereyra's lofted finish over Pickford was of the kind of quality needed if they are to move up the table.
Capoue was destructive in the middle of the pitch - winning more tackles than anyone in a Watford shirt - and also offers obvious grit for the challenges to come.
However, Watford failed to protect their lead before half-time and also struggled for ideas when trying to press home their one-man advantage for the closing 19 minutes.
They failed to force any opening and, when they did risk throwing numbers forward, paid a painful price as Walcott delivered the first home defeat of the Pearson era.
Man of the Match - Yerry Mina
'We have to recover' - manager reaction
Watford boss Nigel Pearson: "This is certainly a lesson for us. It hurts for sure but we will continue to work through it. It's not the end of the world but it's certainly frustrating and annoying.
"We have to recover. Confidence is something that you can build when you get some momentum. Likewise when it goes the other way you have to show some resolve and manage the game better. Game management has let us down today."
Everton manager Carlo Ancelotti: "We were looking to go home with a draw because we had 10 men but we did a fantastic counter-attack.
"Honestly, we didn't deserve to equalise in the first half but I think with what happened last week and this week we deserved to win.
"I think it was the wrong decision by the referee with the red card. I think we were lucky to score at the end. We have to stay focused, improve and be confident because this squad has good quality."
Everton need a clean sheet - key stats
- Watford have failed to win a Premier League game at Vicarage Road after being two goals ahead for the first time, previously winning 23 and drawing twice.
- Everton are without a clean sheet in their past 12 Premier League away games, their longest run without a shutout on the road since October 2003 (13 games).
- Fabian Delph is the 25th player to receive a red card for more than three different sides in the Premier League (Aston Villa, Manchester City and Everton).
- Yerry Mina is the first defender to score two goals in a Premier League game for Everton since Leighton Baines v West Ham in September 2013.
- Watford's Gerard Deulofeu has been directly involved in five goals in his past seven Premier League appearances (two goals, three assists), as many as his previous 22 in the competition.
Everton host Crystal Palace in the lunchtime kick-off next Saturday, 8 February while Watford travel to Brighton in the evening kick-off on the same day.
- 11MasinaBooked at 68mins
- 14ChalobahSubstituted forWelbeckat 57'minutes
- 37PereyraSubstituted forSuccessat 75'minutesBooked at 78mins
- 7DeulofeuSubstituted forPussettoat 82'minutes
- 13MinaBooked at 84mins
- 2HolgateBooked at 86mins
- 10G SigurdssonSubstituted forSchneiderlinat 67'minutes
- 8DelphBooked at 71mins
- 17IwobiSubstituted forKeanat 65'minutes
- 9Calvert-LewinSubstituted forKeaneat 73'minutes
- Craig Pawson
- Shots on Target
Second Half ends, Watford 2, Everton 3.
Foul by Moise Kean (Everton).
Adam Masina (Watford) wins a free kick in the defensive half.
Morgan Schneiderlin (Everton) wins a free kick in the defensive half.
Foul by Christian Kabasele (Watford).
Goal! Watford 2, Everton 3. Theo Walcott (Everton) right footed shot from the right side of the six yard box to the centre of the goal. Assisted by Moise Kean following a fast break.
Attempt missed. Moise Kean (Everton) left footed shot from the centre of the box misses to the right. Assisted by Richarlison following a fast break.
Lucas Digne (Everton) wins a free kick in the defensive half.
Foul by Ignacio Pussetto (Watford).
Mason Holgate (Everton) is shown the yellow card for a bad foul.
Foul by Mason Holgate (Everton).
Abdoulaye Doucouré (Watford) wins a free kick in the attacking half.
Attempt missed. Abdoulaye Doucouré (Watford) right footed shot from outside the box is close, but misses to the right following a set piece situation.
Yerry Mina (Everton) is shown the yellow card for a bad foul.
Foul by Yerry Mina (Everton).
Isaac Success (Watford) wins a free kick on the left wing.
Attempt missed. Abdoulaye Doucouré (Watford) right footed shot from outside the box misses to the left following a corner.
Corner, Watford. Conceded by Morgan Schneiderlin.
Substitution, Watford. Ignacio Pussetto replaces Gerard Deulofeu.