21 points from the boot of Stephen Donald were enough for Bath to tear up the form book and record a narrow 21-18 victory over Harlequins.
Bath were looking to end a run of two defeats, while Harlequins headed into the game in fine form, looking every bit capable of defending their Aviva Premiership crown.
Not a single try was scored on the night, which meant the responsibilities sat on the shoulders of the two teams' goalkickers.
A penalty goal on six minutes from Nick Evans got the ball rolling for Quins, though just over ten minutes later the scores were level courtesy of Donald's first three-pointer of the evening.
Evans' 23rd minute effort put Harlequins back in front and the score remained at 3-6 until the dying minutes of the first half, when a quickfire from brace from Donald turned the deficit on its head and handed Bath the advantage.
Defences continued to dominate throughout the second half and tactical warfare became the name of the game. And on the night there was little between the two teams, as indiscipline from both sides afforded the other the opportunity to keep the scoreboard ticking over.
Donald's effort on 45 minutes put six points between the two teams, though the scores were level by the end of the third quarter courtesy of two booted responses from Evans.
Donald quickly regained the lead for his side on 63 minutes, but Evans was quick in his response to level the scores once again.
As the final ten minutes loomed it was two further Donald penalties, his sixth and seventh of the evening, that handed Bath what would turn out to be an unassailable advantage.
And though Evans responded on 75 minutes, Bath held their discipline and their defence to seal the win.
Pens: Donald 7
Pens: Evans 6
Bath: 15 Nick Abendanon, 14 Kyle Eastmond, 13 Semesa Rokoduguni, 12 Matt Banahan, 11 Tom Biggs, 10 Stephen Donald, 9 Michael Claassens, 8 Simon Taylor, 7 Guy Mercer, 6 Josh Ovens, 5 Dave Attwood, 4 Stuart Hooper (c), 3 Anthony Perenise, 2 Lee Mears, 1 Charlie Beech.
Replacements: 16 Brett Sheehan, 17 Alan Cotter, 18 Kane Palma-Newport, 19 Dominic Day, 20 Ryan Caldwell, 21 Will Skuse, 22 Mark McMillan, 23 Jack Cuthbert.
Harlequins: 15 Tom Williams, 14 Ugo Monye, 13 Matt Hopper, 12 Jordan Turner-Hall, 11 Sam Smith, 10 Nick Evans, 9 Karl Dickson, 8 Nick Easter (c), 7 Luke Wallace, 6 Tom Guest, 5 George Robson, 4 Olly Kohn, 3 Will Collier, 2 Joe Gray, 1 Mark Lambert.
Replacements: 16 Rob Buchanan, 17 Darryl Marfo, 18 Kyle Sinckler, 19 Pete Browne, 20 Joe Trayfoot, 21 Jordan Burns, 22 Rory Clegg, 23 Seb Stegmann.
Referee: JP Doyle