Watford edged into the FA Cup fifth round after a late Odion Ighalo goal against Nottingham Forest at the City Ground.
The Premier League side dominated possession and forced Forest keeper Dorus De Vries into a series of saves during a lacklustre opening half, which ended with Forest forward Jamie Ward wasting the best opportunity to break the deadlock.
Nordin Amrabat was denied a goal on his debut by a stunning De Vries save before Quique Sanchez Flores brought on Odion Oghalo, and the Hornets’ leading scorer duly netted a late winner with practically his first touch.
Teenage striker Kelechi Iheanacho gave Manchester City fans an exciting glimpse into the future by scoring his first hat-trick as Manuel Pellegrini’s men cruised into the FA Cup fifth round and kept their hopes alive of an unprecedented Quadruple.
With Sergio Aguero given a rest, Iheanacho took centre-stage with his sixth, seventh and eighth goals of the campaign, against the Premier League’s bottom team.
He followed up a poacher’s finish after four minutes with a coolly-taken penalty
midway through the first half and completed his treble following a howler by ex-Manchester City defender Micah Richards. Raheem Sterling then added a late fourth.
Villa came into the match unbeaten in five games and held City to a goalless draw at Villa Park in November, but they offered little resistance in a dreadful performance.