Brighton moved the ball about with more cohesion and took their seventh point out of the last nine since Virgo has been drafted in to lead the attack.
Earlier it had looked as if Watford's top scorer Danny Webber was going to give his side all three points with a neat piece of opportunism seven minutes into the second half.
But while both teams enjoyed some good approach work at times, their performances in the last third of the field failed to impress.
Michels Kuipers did not really have a save to make and apart from a reflex save from a deflected cross, Richard Lee was similarly untroubled.
Watford's Gavin Mahon had two successive shots blocked in the first half and after a defensive lapse on behalf of Brighton, Heidar Helguson raced in, but hit the loose ball well over the target.
It was a similar first half story for Brighton with Dean Hammond lofting the ball over the target from an Adam El-Abd cross and then when an Alexis Nicolas drive bounced awkwardly in front of the keeper, Lee pushed it for a corner.
Watford came out in a more determined manner after the break and Neal Ardley changed the direction of play with a ball out to Neil Cox.
He chipped it into the middle and Webber, who appeared to time his run to perfection, was in the clear, drawing Kuipers and slotting home from close range.
But Watford failed to bid on that lead and gradually Brighton had an increase in possession which forced Watford onto the back foot.
Then in the 85th minute a succession of defensive errors allowed Darren Currie to flight the ball into the path of Virgo and he beat Lee with a glorious shot for the equaliser.