Brilliant save from Ryan Allsop!
That's a superb stop to deny Ben Cabango as he tips his effort over the bar.
Watford are in total control of this game now, that third goal has really taken the sting out of Luton.
Keinan Davis, whose third-minute goal set the home side on their way, has been exceptional today, but he has gone off injured to be replaced by Vakoun Bayo in the only negative so far for the Hornets.
Jordan Clark has a snap shot from distance which is comfortably saved by Daniel Bachmann in the Watford goal.