FA Cup holders Arsenal crashed out of the competition on Sunday as Watford won 2-1 at the Emirates Stadium in a dramatic tie.
Goals from Odion Ighalo and Adlene Guedioura gave Watford a deserved advantage in the second half as the Gunners struggled to find the target, suffocating under waves of counter-attacks from the visitors.
Substitute Danny Welbeck gave Arsenal hope with a goal in the final moments, but the hosts' lack of finishing led to their downfall.
The Hornets gave one of their best performances of the season, taking their place in the last four and booking a trip to Wembley.