Arsenal kept their faint hopes of the Premier League title alive with an easy victory over a poor Watford side.
The Gunners led inside four minutes - Alexis Sanchez slotting in from close range - and controlled the first half.
Alex Iwobi forced Heurelho Gomes into a stunning save and soon doubled their advantage by sweeping in from 12 yards to finish off a superb team move.
Hector Bellerin's shot deflected in for Arsenal's third, while substitute Theo Walcott completed the rout late on.
All too late for Arsenal?
Arsenal had lost three straight home games in all competitions going into the match, but this was a routine win as they closed the gap to leaders Leicester to eight points.
Arsene Wenger's side still need an unlikely collapse from both the Foxes and second-placed Tottenham to have any hope of securing the league title, while tough trips to West Ham and Manchester City await in their remaining seven games.
