Match ends, Watford 3, Everton 2.
Watford 3-2 Everton
Stefano Okaka scored his first goals for Watford as they came from behind to beat out-of-form Everton in the Premier League.
Okaka, signed from Anderlecht in the summer, flicked in a superb backheeled effort in the first half, before heading home following a corner after the break.
In between, Sebastian Prodl powerfully nodded in from Jose Holebas' whipped cross.
Everton had gone ahead on 17 minutes as Romelu Lukaku slotted in from Gareth Barry's inch-perfect, first-time pass, and the Belgian headed in a late consolation.
Eleven different nationalities, one Watford
The Hornets had lost three of their past four league games, and looked like stretching that sequence when they fell behind early on.
But they drew inspiration from striker Okaka's stunning opener, the Italian's first goal in the Premier League since scoring for Fulham in May 2010.
His second was helped by slack Everton defending, which allowed him to head in at the near post.
Their starting line-up featured players of 11 different nationalities, but Watford's togetherness was clear. Indeed it was epitomised by the hard-working Etienne Capoue, who covered 9.33km and gained possession back nine times - more than any other team-mate.
Captain Troy Deeney remains stuck on 99 club goals, though, and has now gone eight league matches without finding the net. He should have done better with a first-half effort he screwed wide.
Toffees unstuck at the back
After a bright start to the season under Ronald Koeman, with four victories in their opening five games, Everton have fallen away and have won just one of their past 10.
And problems in defence have seen them keep just two clean sheets in the league so far this season.
Austrian defender Prodl gave their backline a warning when he headed over, but they did not respond and he soon found the net.
Lukaku did provide some cheer at the other end, and his header five minutes from time took his tally of goals to 12 in the league this season.
Barry closes in on record
Veteran Everton midfielder Barry has played in 609 top-flight games, moving him level with former England team-mate Frank Lampard.
The 35-year-old showed his class with a wonderful assist for Lukaku's opener and made more passes (62) and tackles (four) than any other player.
If the former Aston Villa and Manchester City man plays in Everton's remaining 23 league games this season, he will draw level with Ryan Giggs' Premier League record.
Man of the match - Stefano Okaka (Watford)
'A victory for the fans'
Watford manager Walter Mazzarri:
"I am really happy. Even though they managed to score with their first chance, we showed character to beat a very good team. I also want to thank the fans because they were incredible. When we were losing, they were still chanting for us."
"Stefano Okaka had to wait mainly because of injury but he has shown how important he is for the team."
Everton boss Ronald Koeman:
"I did not expect an easy job when we came to Everton."
"I know the expectations, I know the criticisms of the past few seasons. When I signed this contact I did not expect an easy job. I know the history of the club."
"The Premier League is not always about football quality, it's about physicality and winning second balls and in that aspect the team is too weak."
"We have difficulty against direct, aggressive teams. In that aspect we need to improve and do better and that's the big concern."
"You can't do that in two weeks, you need January and the summer. We need a better balance in our team."
Analysis - 'Koeman and fans will be worried'
Former Premier League goalkeeper Mark Schwarzer on BBC Radio 5 live:
Watford definitely deserved to win the game. Everton were well below standard and you can understand why they are in the run they are in.
For most of the game, Everton really didn't pose many threats. Looking at the run of games they have to come, Ronald Koeman and their fans will be extremely worried.
Everyone chipping in for Watford
- Watford won against Everton for the first time in any competition since March 1987, following two draws and nine defeats.
- Everton have conceded 11 goals in their past four away games in the Premier League, including three or more on two occasions.
- Romelu Lukaku has been directly involved in 12 goals (nine scored, three assists) in the Premier League this season.
- At the age of 23, Lukaku has scored against 22 of the 29 different opponents he has faced in the top flight.
- Watford have had 11 different goalscorers in the Premier League this season, a joint-high alongside Liverpool.
- Stefano Okaka netted his first Premier League goal in 2,414 days; last scoring in May 2010 for Fulham against West Ham.
- Everton have now lost their past four Premier League away games, their worst such run in the competition since January 2015 (five defeats).
- Watford's Jose Holebas has provided three assists this season, a league-high for a defender alongside Bournemouth's Adam Smith.
Watford travel to face Manchester City in the league on Wednesday (kick-off 20:00 GMT), a day after Everton host Arsenal (19:45).
- 18ZuñigaSubstituted forKabaseleat 90+3'minutes
- 25HolebasBooked at 74mins
- 17GuédiouraBooked at 7minsSubstituted forJanmaatat 61'minutes
- 7N Amrabat
- 33OkakaSubstituted forWatsonat 81'minutes
- 25Funes Mori
- 3BainesBooked at 62minsSubstituted forLennonat 83'minutes
- 17GueyeSubstituted forBarkleyat 64'minutes
- 7DeulofeuBooked at 14mins
- 11MirallasSubstituted forE Valenciaat 71'minutes
- 19E Valencia
- Anthony Taylor
- Shots on Target
Second Half ends, Watford 3, Everton 2.
Romelu Lukaku (Everton) wins a free kick in the attacking half.
Foul by Valon Behrami (Watford).
Hand ball by Enner Valencia (Everton).
Substitution, Watford. Christian Kabasele replaces Juan Zuñiga.
Attempt saved. Ross Barkley (Everton) right footed shot from outside the box is saved in the top centre of the goal.
Enner Valencia (Everton) wins a free kick in the attacking half.
Foul by Etienne Capoue (Watford).
Attempt missed. Romelu Lukaku (Everton) left footed shot from a difficult angle on the left misses to the right. Assisted by Ross Barkley.
Attempt saved. Romelu Lukaku (Everton) left footed shot from outside the box is saved in the centre of the goal. Assisted by Ross Barkley.
Goal! Watford 3, Everton 2. Romelu Lukaku (Everton) header from the centre of the box to the bottom left corner. Assisted by Aaron Lennon with a cross following a corner.
Attempt blocked. Ashley Williams (Everton) header from the centre of the box is blocked. Assisted by Gerard Deulofeu with a cross.
Corner, Everton. Conceded by José Holebas.
Attempt missed. Enner Valencia (Everton) header from the centre of the box is close, but misses to the right. Assisted by Aaron Lennon with a cross.
Offside, Watford. Sebastian Prödl tries a through ball, but Daryl Janmaat is caught offside.
Offside, Everton. Gerard Deulofeu tries a through ball, but Romelu Lukaku is caught offside.
Substitution, Everton. Aaron Lennon replaces Leighton Baines.
Substitution, Watford. Ben Watson replaces Stefano Okaka.
Attempt missed. Enner Valencia (Everton) right footed shot from outside the box misses to the right. Assisted by Leighton Baines with a headed pass.
Corner, Everton. Conceded by Sebastian Prödl.
Attempt blocked. Ross Barkley (Everton) left footed shot from the centre of the box is blocked. Assisted by Gerard Deulofeu.
Foul by Nordin Amrabat (Watford).
James McCarthy (Everton) wins a free kick in the attacking half.
Corner, Everton. Conceded by Juan Zuñiga.
Sebastian Prödl (Watford) wins a free kick in the defensive half.
Foul by Enner Valencia (Everton).
José Holebas (Watford) is shown the yellow card.
Foul by Stefano Okaka (Watford).
Gareth Barry (Everton) wins a free kick in the defensive half.
Substitution, Everton. Enner Valencia replaces Kevin Mirallas.
Troy Deeney (Watford) wins a free kick in the attacking half.
Foul by Ashley Williams (Everton).
Attempt missed. Romelu Lukaku (Everton) right footed shot from the right side of the six yard box misses to the right. Assisted by Gerard Deulofeu.
Substitution, Everton. Ross Barkley replaces Idrissa Gueye.
Goal! Watford 3, Everton 1. Stefano Okaka (Watford) header from the centre of the box to the bottom left corner. Assisted by José Holebas with a cross following a corner.
Corner, Watford. Conceded by Maarten Stekelenburg.
Attempt saved. Miguel Britos (Watford) header from a difficult angle on the left is saved in the top centre of the goal. Assisted by Etienne Capoue with a cross.
Delay over. They are ready to continue.
Leighton Baines (Everton) is shown the yellow card for a bad foul.