It was deserved because anything other than a win for the Whites would have been outrageous but their failure to put the game to bed always left them vulnerable to what happened in the 73rd minute.
With the score at 1-0 former Leeds defender Danny Rose whipped over a corner, Ilan Meslier let the wet ball slip through his fingers and it bounced into the net off the back of Liam Cooper. Referee Simon Hooper did what all referees do when a goalkeeper drops the ball and looked for a reason to give a free-kick.
Watford substitute Christian Kabasele had given him the excuse he wanted, wrestling with Cooper as the ball came over. Who was more guilty was open to debate but who was going to get the free-kick was not.
In the end, though, justice was done. For Leeds to have not got their first win of the season after such a good performance, led by Dan James but with plenty of willing accomplices, would have been a travesty.
Try as they might, Leeds just could not add to Diego Llorente's opportunistic 18th-minute goal, having 20 shots but only three on target. They were denied a penalty in the first half and hit the crossbar in the dying stages of the second through Tyler Roberts, but in the end they had to settle for 1-0.
Coming into the game, coach Marcelo Bielsa insisted his team were not short of confidence despite being without a Premier League win this season and they played in a way that proved his point.
Sliding into tackles on a wet surface and pressing voraciously in Watford faces from the start, there was a familiar intensity about the home team's football.
Llorente, back in the side after injury, fizzed a lovely pass into Mateusz Klich, played a good one over the top to Raphinha, and picked out James with another. There was also a thundering tackle on Kiko Femenia early on.
Perhaps enjoying the pace of the game, James produced his best performance in a Leeds shirt, whilst Raphinha just maintained his usual standards. Rodrigo's movement made their jobs easier.
It was all made to keep the Elland Road atmosphere bouncing.
Raphinha, cutting inside, and James had shots blocked in the eighth minute ad Ben Ben Foster was forced to save from Stuart Dallas three minutes later after Rodrigo forced the ball through to him. Foster swept the rebound to safety with his foot.
A goal was coming, even if the source and manner were not quite as expected, Rodrigo's chop-back winning a corner Raphinha sent over and when the ball more or less bounced off Juraj Kucka's stooping head, Llorente showed centre-forward instincts to put the loose ball away.
Leeds continued to pile forward.
Quickly after the goal William Ekong wrapped an arm around James and although it was made to look worse by the defender collapsing on top of the winger when he was already going down for the grappling it was incredible if, as seemed to be the case, video assistant referee Lee Mason did not think the penalty-area incident worthy of another look. Leeds fans certainly wanted to know if he had gone to make a cup of tea at the wrong moment.
Rodrigo's touch let him down from a Raphinha pass, Dallas had a shot blocked and Francisco Sierralta needed a good intervention from James's cross. When Rodrigo played Raphinha in, he took it around Foster but the angle beat him.
At that stage, a hammering looked on the cards.
But a bit of faffing around from Llorente in the 28th minute, allowing Ozan Tufan a shot he did not make the most of, was warning not to take anything for granted.
Raphinha headed a good cross off target, then blazed over after Dallas carried the ball towards goal and Klich volleyed into the side netting to keep the half-time damage to 1-0.
The start of the second half was a bit of a siege but it was his defenders, not goalkeeper Ben Foster, who was made to work hard.
Dallas and James hit shots into defenders, Raphinha blazed a free-kick over, and Dallas was off target when he was picked out just outside the D as Kucka dived across him. Rodrigo had a shot blocked.
The best chance was a Raphinha corner on the hour, which Foster had to claw from under his crossbar.
Watford were largely able to stop James with a succession of fouls, some earning yellow cards.
Meslier had to come out and save at the feet of Emmanuel Dennis, then got lucky from the corner.
More chances followed, most notably when Kucka cleared off the line from Roberts, then heard the ball clang above his head as the substitute had a second try.
Another goal was not coming for Leeds but at least a much-needed win did.
Leeds United: Meslier; Shackleton, Llorente, Cooper, Firpo; Phillips; Raphinha, Dallas (Roberts 78), Klich (Struijk 90), James; Rodrigo.
Unused substitutes: Klaesson, Harrison, Gelhardt, Hjelde, Cresswell, McKinstry, Greenwood.
Watford: Foster; Femenia, Troost-Ekong, Sierralta (Kabasele 68), Rose; Kucka, Sissoko; Sarr, Tufan (Joao Pedro 59), Dennis; King (Sema 45).
Unused substitutes: Ngakia, Cleverley, Masina, Gosling, Bachmann, Hernandez Suarez.
Referee: S Hooper (Swindon).