Dean Saunders, Wolves' fourth manager in 12 months, is still waiting for his first victory in charge having overseen nine of their run of 13 winless matches, with Wanderers - in the Championship drop zone - still facing the very real prospect of successive relegations, as they experienced in the 1980s.
Yet Sako's well-taken injury-time equaliser drew welcome celebrations from a frustrated Wolves crowd, who will still believe in survival.
The game's defining moment of brilliance looked to have came just before half-time as Watford playmaker Almen Abdi, one of a contingent of players on loan from Udinese, converted a delightful free-kick for his 10th goal of the season.
The Hornets could at that point thank goalkeeper Jonathan Bond, making his full league debut for the Hertfordshire outfit, for still being on level terms having made an impressive double save.
It was a point towards Watford's march to a Premier League return, but Gianfranco Zola's second-placed side will certainly see it as two dropped.
The first clear chance of the game came in the 19th minute when Kevin Doyle found possession on the edge of the area and saw his effort well parried by Bond, in for the injured Manuel Almunia, who got up quickly to superbly keep out Bjorn Sigurdarson's rebound.
Marco Cassetti fired straight at Carl Ikeme following Jack Robinson's mis-control and as the game was drawing towards stalemate at half-time, the visitors broke the deadlock.
Vydra drew a soft foul from Wanderers skipper Karl Henry and Abdi, 20 yards out from a central position, floated a super free-kick over the wall.
Watford should have doubled their advantage in the 66th minute but Ikechi Anya somehow failed to convert after being teed up by the impressive Cassetti, with Cristian Battocchio drilling narrowly over from distance minutes later.
Wolves wasted a chance to draw level in the 77th minute, Sigurdarson seeing his shot saved by Bond before Robinson was well off target with the rebound.
Yet, with the game seeming beyond them, Sako popped up to convert from Matt Doherty's long throw-in.
Watford substitute Fernando Forestieri still had a chance to snatch matters but blew his shot off target.