Match ends, Watford 0, Arsenal 3.
Arsenal produced a superb second-half display to defeat Watford and move into second place in the Premier League.
Alexis Sanchez opened the scoring after the break when he pounced on the loose ball after Mesut Ozil appeared to be fouled and fired in.
Olivier Giroud slammed in the second, before Aaron Ramsey slotted in his first for the club this season.
Watford's best chance came in the first half when Odion Ighalo screwed his shot wide from 12 yards.
Could an on-song Ramsey mean this is Arsenal's season?
It remains a big 'if', but if Ramsey can rediscover the form he showed in the first half of the 2013-14 season then Arsenal could land their first league title since 2004.
The Wales international was on a remarkable run two seasons ago, scoring 13 goals in 27 appearances to lead Arsenal's charge at the top of the table. However, in December he suffered a thigh injury which kept him out of action until April - and with it went Arsenal's title chances.
This season the Gunners' goals have largely come from Sanchez, Giroud and Theo Walcott. Ramsey had a chance to join the list in the first half but missed with what was his 26th effort on goal - more than any other Premier League player who has not scored yet this season.
But having notched for Wales last week, he finally grabbed his first for his club when he converted Hector Bellerin's through-ball, albeit via a slight deflection off Ikechi Anya.
Gunners' big guns firing
Ramsey became the latest member of Arsenal's strong attacking unit to find the net today.
Walcott, with four goals this season, failed to make an impact at Vicarage Road, but manager Arsene Wenger had Giroud in reserve. And although Sanchez and Ozil were relatively anonymous in the first half, they displayed their class after the break and were ruthless as Watford's usually resilient defence tired.
Some would criticise Ozil's lack of goals - only one so far this season - but the German World Cup winner provided two assists.
If they all find some consistency in the league then Arsenal fans will no doubt get value for money this campaign.
Man of the match - Mesut Ozil (Arsenal)
Arsenal boss Arsene Wenger, speaking to BBC Sport:
"It was an important win for us. You could see why Watford have not conceded many goals at home. They are strong and very direct and we could not make a mistake.
"When we scored the first goal I like the fact we were relentless and continued to attack. The confidence is there and once we were 1-0 up or 2-0 up we continued to play and attack.
"Physically and mentally the game became more difficult for Watford as well and we took advantage of that."
Watford boss Quique Sanchez Flores, speaking to BBC Sport:
"I'm a little frustrated. In the first half we played really well.
"We have to make an amazing effort if we want to make the level. We have to be positive with our first hour. The match was finished in a 10-15 minute spell.
"I am really happy with the first half performance. We had chances and I felt we would get the first goal."
The stats you need to know
- Watford have never won a Premier League game in the month of October (D4 L6).
- The Gunners have won their last six meetings with the Hornets in all competitions, including all five previous Premier League clashes.
- Watford conceded as many goals in this game (three) as they had in their previous six top-flight matches at Vicarage Road combined.
- Ramsey scored his first goal of the season in the Premier League, after failing to net with his previous 26 (inc. blocked) in 2015-16.
- Watford striker Troy Deeney has now had the most shots without scoring in the Premier League this season (23 shots inc. blocked).
Arsenal face a huge test against Bayern Munich in midweek in the Champions League - a match they really have to win - before they host Everton next weekend. Watford, who dropped to 14th in the Premier League, are at Stoke.
- 1GomesBooked at 63mins
- 2NyomBooked at 47minsSubstituted forBerghuisat 69'minutes
- 21AnyaSubstituted forParedesat 81'minutes
- 22AbdiSubstituted forIbarboat 75'minutes
- 4MertesackerBooked at 58mins
- 11ÖzilSubstituted forArtetaat 81'minutes
- 17SánchezSubstituted forOxlade-Chamberlainat 80'minutes
- 14WalcottSubstituted forGiroudat 64'minutes
- Mike Jones
- Shots on Target
Second Half ends, Watford 0, Arsenal 3.
Foul by Olivier Giroud (Arsenal).
Etienne Capoue (Watford) wins a free kick on the left wing.
Attempt missed. Olivier Giroud (Arsenal) left footed shot from the left side of the box is too high.
Offside, Arsenal. Francis Coquelin tries a through ball, but Olivier Giroud is caught offside.
Alex Oxlade-Chamberlain (Arsenal) wins a free kick on the left wing.
Foul by Juan Carlos Paredes (Watford).
Francis Coquelin (Arsenal) wins a free kick in the defensive half.
Foul by Etienne Capoue (Watford).
Attempt missed. Troy Deeney (Watford) right footed shot from the left side of the box is close, but misses to the left. Assisted by Odion Ighalo.
Corner, Arsenal. Conceded by Steven Berghuis.
Corner, Arsenal. Conceded by Craig Cathcart.
Corner, Arsenal. Conceded by Nathan Aké.
Corner, Arsenal. Conceded by Heurelho Gomes.
Attempt saved. Olivier Giroud (Arsenal) header from the centre of the box is saved in the top right corner. Assisted by Santiago Cazorla with a cross.
Corner, Arsenal. Conceded by Nathan Aké.
Substitution, Watford. Juan Carlos Paredes replaces Ikechi Anya.
Substitution, Arsenal. Mikel Arteta replaces Mesut Özil.
Substitution, Arsenal. Alex Oxlade-Chamberlain replaces Alexis Sánchez.