Lee Gaskell emerged as the hero, staying cool under immense pressure to slot from almost 40m out with the very last play of a nerve-shredding West Yorkshire derby.
Let’s not forget, his side twice fell to single point defeats against Leeds last season, Luke Gale both times nailing the crucial drop-goal.
England scrum-half Gale, however, was not present today, one of 11 first-teamers missing as the Rhinos suffered a fifth successive defeat.
How Huddersfield were grateful.
Kicking duties instead fell to Liam Sutcliffe who had put his side 14-13 ahead with his third attempted drop-goal effort in the 76th minute. Even that, though, bounced over off the crossbar.
And the home side then won back a short restart via Ricky Leutele to quickly level with a one-pointer from two-try Aidan Sezer, the Australian scrum-half who had already seen one shot barely get off the ground.
Yet, in the increasingly crazy final stages, Leeds prop Matt Prior ripped possession clear from Michael Lawrence to give Sutcliffe another chance from just 15m out and in front only for it to be fluffed once more.
The stand-off, who otherwise had an excellent game, was then penalised for ball-stealing on Jermaine McGillvary.
That put Giants in position to strike once more but, bizarrely, Sezer - the ‘marquee’ signing who has been linked with a return to the NRL with Brisbane Broncos in 2022 - tried running down a short side and lost the ball in an ill-fated play that looked sending the contest to Golden Point extra-time.
Nevertheless, Leeds - who had fought back admirably having looked frayed earlier in the second half - infringed once more with another ball-steal.
Huddersfield worked down field and, as Sezer was put under pressure, he flung the ball back further still to Gaskell, the rangy full-back who kicked from distance with the toughest effort of the lot and the clock literally ticking down to zero seconds.
Huddersfield had also lost by a single point against Warrington Wolves last term as well as falling 25-24 at Hull KR this year; turning narrow defeats into victories was part of Watson’s mandate when coming in.
It has taken him five outings to finally get off the mark but he will hope this now kicks them on.
They should really have put the game to bed much earlier.
Giants extended their 6-4 interval lead just 47 seconds into the second period when Gaskell surged clear from inside his own half and Sezer supported.
Sezer improved and then added a penalty soon after as Leeds - with Konrad Hurrell twice throwing away possession in his own half - endured a miserable spell.
Adam O’Brien dummied over from close range but that was ruled out after an infuriated Kenny Edwards had, for some reason, squared up with Kruise Leeming at the play-the-ball.
Luke Yates also got over the line but spilled when trying to score.
Instead, against the run of play, Sutcliffe made a searing break for Ash Handley to score, Rhyse Martin converting and Martin added a penalty soon after to level it at 12-12 on the hour.
Even then, Giants should have advanced but James Gavet badly erred in good position and Josh Jones had another try ruled out before that frantic finish.
The first half had been much like the second; full of endeavour from both sides but little quality.
The hosts thought they had taken the lead in the tenth minute when Rhinos full-back Jack Broadbent found himself in no man’s land trying to get to Jack Cogger’s towering kick and Sezer picked up the loose pickings.
However, the Giants captain was deemed to have been offside with his chase.
Sezer did eventually score on the half-hour mark but, in all honesty, it had been Huddersfield’s only other genuine attacking threat of note.
Leeds players, meanwhile, must feel like they have had more different half-back combinations than Covid tests this season.
The latest saw hooker Leeming play at No7 - alongside centre Sutcliffe - after Kyle Eastmond pulled a hamstring in their final training session yesterday.
They did open the scoring on 15 minutes, Sezer doing well to prevent Matt Prior when the Australian prop looked destined to score but helpless at the next play when Bodene Thompson exploited Giants’ stretched defence.
Huddersfield struggled to apply any pressure and, when they had chance from a, Joe Greenwood spilled early in the tackle count and then compounded his error with a high tackle on Prior.
It became a common theme of self-inflicted damage for Watson’s side.
That said, Leeds needlessly tried shifting the ball in their own 20 to hand over possession for Sezer to put on his big step for his try.
He converted and eventually his side got home.
Huddersfield Giants: Gaskell; McGillvary, McQueen, Leutele, McIntosh; Cogger, Sezer; Yates, Cunningham, Gavet, Jones, Edwards, Greenwood. Substitutes: Wood, O’Brien, Lawrence, English.
Leeds Rhinos: Broadbent; T Briscoe, Hurrell, Mellor, Handley; Sutcliffe, Leeming; Oledzki, Dwyer, Prior, Walters, Thompson, O’Connor. Substitutes: Martin, Vuniyayawa, Donaldson, L Briscoe.
Referee: Liam Moore (Wigan)