In truth it was a match that could only have been played between two relegation candidates. Had the tension not been hanging in the air the crowd would have been in the warmth of the clubhouse bar long before the final whistle, so poor was the quality.
As it was, the tension mounted, and every mistake was seized upon by a raucous crowd as though they were witnessing the rugby spectacle of all time.
Quins it was who took the lead on the half-hour, with Jeremy Staunton landing a long penalty after a Leeds forward had strayed offside. The kick brought to a close thirty minutes of tough enterprise, strewn with hard hits and nervy errors, which Leeds just about shaded on the strength of their pack efforts.
The penalty did not do anything to significantly improve the quality, but Leeds re-doubled their blustering efforts, and finally reaped the reward a minute before the break, with Andre Snyman rounding off a simple back-line move in the right-hand corner.
Gordon Ross utilised the three-minute break for TMO consultation to catch his breath and gain composure, and he landed a wonderful touchline conversion to take the Tykes in 7-3 up at the break.
Quins began the second half with a monstrous stroke of fortune, when Staunton picked off Ross' flat pass to scamper in under the posts, and put themselves back in the lead at 10-7.
With all their work of the first half undone Leeds might have been forgiven for thinking this was not their night. Several rubs of the green were not going their way, and when Diego Albanese fired the simplest of scoring passes over Ross' head, doubts formed on spectators' faces all over the ground.
It added to the mounting tension, but the match's first moment of genuine quality gave Leeds the lead back again. A glittering back-line move, involving some eight sets of hands began with Regan turning over the ball near his own 22, and culminated with Tom Biggs' discreet pop to man-of-the-match Phil Christophers inside him for the Tykes' second. Again, Ross converted magnificently.
Quins wilted visibly after that, and after a sustained spell of pressure, Snyman took a superb switch pass from Alan Dickens and crashed over near the posts. Ross could hardly miss.
Leeds kept up the pressure in injury time, and almost stole an unlikely bonus point, but Regan put his head down and charged when a simple draw and pass would have seen Bell home.
It mattered not. Harlequins must now square up to Sale at the Stoop on Saturday, knowing that only a win will keep them in the top flight. A loss at home to the Sale team that needs the win to qualify for the Zurich Premiership semi-final will consign one of England's most famous names to the drop. Any one of five clubs could still go down though, with two of them playing off against each other when Worcester host Northampton at Sixways. What a weekend this is going to be now!
Man-of-the-match: Phil Christophers' quality shone long before he took the pass for his scintillating try. He made his presence felt all over the field, and led Leeds to their win with his creativity. Mark Regan also had a fine game up front.
For Leeds:Tries: Snyman 2, ChristophersCons: Ross 3
For Harlequins:Try: StauntonCon: StauntonPen: Staunton
Leeds: 15 Albanese, 14 Andre Snyman, 13 Phil Christophers, 12 Chris Bell, 11 David Rees , 10 Gordon Ross, 9 Alan Dickens, 8 Alex Popham, 7 Richard Parks, 6 John Dunbar, 5 Scott Morgan, 4 Stuart Hooper, 3 Gavin Kerr, 2 Mark Regan, 1 Mike ShelleyReplacements: 16 Rob Rawlinson, 17 Holt, 18 Dan Hyde, Mark McMillan, 19 Craig McMullen, 20 Tom Biggs, 21 Colm Rigney, 22 Rob Rawlinson
Harlequins: 15 Tom Williams, 14 George Harder, 13 Will Greenwood, 12 Dafydd James, 11 Ugo Monye, 10 Arwel Thomas, 9 Steve So’oialo, 8 Tony Diprose, 7 Andre Vos (C), 6 Nick Easter, 5 Simon Maling, 4 Jim Evans, 3 Ceri Jones, 2 James Hayter, 1 Mike Worsley Replacements: 16 Ace Tiatia, 17 Jon Dawson, 18 Simon Miall, 19 Luke Sherriff, 20 Simon Keogh, 21 Jeremy Staunton, 22 Gavin Duffy
Referee: Chris WhiteTouch Judges: Steve Savage / Brian CampsallAssessor: Colin HighTelevision Match Official: David Matthews