Southampton's Shane Long scored the fastest goal in Premier League history but Andre Gray's late strike secured a 1-1 draw for Watford.
The Republic of Ireland international closed down Craig Cathcart's attempted clearance and powered through to clip over Ben Foster after just seven seconds.
The previous record holder was Ledley King, who scored in just under 10 seconds during Tottenham's win over Bradford City in 2000.
Watford goalkeeper Ben Foster twice denied Nathan Redmond with excellent saves before Gray popped up in the 90th minute to ensure a share of the spoils.
A point moves Ralph Hasenhuttl's side six points above 18th-place Cardiff City, while Watford leapfrogged Everton into seventh.