Watford keeper Heurelho Gomes says Arsenal lack confidence and the Hornets had a game plan to dump the Gunners out the FA cup.
The former Tottenham and PSV goalkeeper said Watford had been confident of victory.
"When you see Arsenal playing against big teams, they look like a small team," Gomes, who did not play in the fixture, told ESPN Brazil.
"They don't look like winning a title soon. They are not strong defensively. It is the best time to play Arsenal and we came to the match very confident.
"We knew once we had the ball we'd be able to pass it around, since Arsenal give you too much space."