A Nick Easter try long after the full-time hooter handed Harlequins a 13-11 win over Bath in the Guinness Premiership on Saturday.
Harlequins' first win of the season could not have come in more dramatic circumstances as Easter's try came at the end of a titanic battle.
Bath looked like hanging on in the face of relentless pressure, but the video official finally resolved a fierce contest before Nick Evans added the winning conversion from in front of the posts.
Six months ago, Quins completed a league double over Bath, winning 19-3 at The Rec.
But the grim headlines generated by the clubs' respective scandals since then have left two great rugby traditions battling to restore their reputations.
But the history of the fixture meant more to supporters than the events of the summer, and an 11,203 crowd turned out.
England manager Martin Johnson and attack coach Brian Smith were in attendance, not least to assess the form of Ugo Monye of Harlequins and Bath's Nick Abendanon, possible candidates for the fullback jersey during the autumn internationals.
Bath took early control to such an extent that Quins were reduced to scrapping just to escape from their half.
Referee Wayne Barnes hammered Harlequins with three penalties inside the opening 10 minutes, fly-half Nicky Little firing one for an unsuccessful lineout, the other two between the posts to put Bath 6-0 ahead.
The crowd's anxiety switched to resounding support when Evans boomed over a 40-yard penalty after 16 minutes, but Bath retained the edge in territory and possession until Abendanon allowed an Evans up-and-under to bounce in his 22, and was promptly nailed by the former All Black.
That gave Quins their first opportunity to press into Bath's final quarter, and their increased tempo presented Evans with a penalty kick after 33 minutes, but it was hooked wide from 30 yards.
As the first half drew to a close, it was Quins asking the questions of Bath's defence only to discover they had the correct answers.
And with seconds remaining, a searing break by Little looked to have released Matt Carraro for the first try only for Monye to snuff out the danger with a tremendous tackle.
Quins thought they had scored their first home try of the season in the 54th minute when Monye pounced on a scramble and touched down by the left wing flag. But the score was disallowed for a knock-on by Gonzalo Tiesi.
Evans had a chance to haul Quins level after 63 minutes, but his 28-yard penalty sailed hopelessly wide.
South Africa hooker Gary Botha received a standing ovation when he left the field after 65 minutes. Botha is returning to the Republic for family reasons after two years at Twickenham Stoop.
Quins piled on the pressure, but Bath's defence was resolute, denying Gonzalo Camacho and Danny Care when they looked to have escaped the cover.
With one minute of normal time remaining, Evans kicked his second goal of the night to level at 6-6, only for shocking defence to seemingly hand the game to Bath, Shontayne Hape virtually strolling over on the right.
It looked all over, only for Quins to roar through the gears and batter their way to a win that seemed beyond them.
Pen: Evans 2
Harlequins: 15 Mike Brown, 14 David Strettle, 13 Gonzalo Tiesi, 12 Tosh Masson, 11 Ugo Monye, 10 Nick Evans, 9 Danny Care, 8 Nick Easter, 7 Will Skinner (c), 6 Chris Robshaw, 5 Jim Evans, 4 Lewis Stevenson, 3 John Andress, 2 Gary Botha, 1 Ceri Jones.
Replacements: 16 Aston Croall, 17 Tani Fuga, 18 James Johnston, 19 Shane O'Connor, 20 Tom Guest, 21 Gareth Williams, 22 Rory Clegg, 23. Gonzalo Camacho.
Bath: 15 Nick Abendanon, 14 Joe Maddock, 13 Matt Carraro, 12 Shontayne Hape, 11 Matt Banahan, 10 Nicky Little, 9 Michael Claassens (c), 8 Ben Skirving, 7 Julian Salvi, 6 Andy Beattie, 5 Stuart Hooper, 4 Peter Short, 3 Duncan Bell, 2 Pieter Dixon, 1 David Flatman.
Replacements: 16 Rob Hawkins, 17 David Barnes, 18 Aaron Jarvis, 19 Danny Grewcock, 20 Jonny Faamatuainu, 21 Scott Bemand, 22 Ryan Davis, 23 Jack Cuthbert.
Date: Saturday, October 3
Kick-off: 18:05 BST
Venue: Twickenham Stoop
Referee: Wayne Barnes