Substitute Juan Camilo Zuniga condemned Manchester United to a third defeat in a row in all competitions after putting Watford 2-1 ahead at Vicarage Road on Sunday before winning a stoppage-time penalty that Troy Deeney converted to give the Hornets a 3-1 win over troubled United on Sunday.
Zuniga had put Watford 2-1 in front with less than 10 minutes to go, less than 60 seconds after entering the game. The Red Devils are now six points behind neighbours Manchester City and already look off the pace in the Premier League title race.