A late try from replacement Maurie Fa'asavalu helped Harlequins to a 14-6 win over Bath at the Stoop on Saturday.
The result sees Harlequins regain the lead in the Aviva Premiership standings after an attritional battle on a hot afternoon.
Try-scoring opportunities were at a premium throughout in South West London as players seemed to struggle with the heat at times.
20-year-old Tom Heathcote put the visitors ahead with a penalty in the opening minutes but Quins were quick to respond with some typically free-flowing rugby, resulting in a penalty which Nick Evans converted to level the scores.
Both sides created a few chances as the half wore on, the best of which fell to Michael Claassens, who was denied by a vital last gasp tackle from Mike Brown when he had the try-line at his mercy.
And Bath's cause was not helped midway through the first half as their captain Francois Louw was forced from the field with a knee injury.
They took the lead after 32 minutes though with another Heathcote penalty, which came just moments after Joe Marler had been sent to the sin bin for a high tackle on Tom Biggs.
And the men from the West Country were fortunate to retain their 6-3 advantage going into the break as Evans missed two relatively simple attempts at goal in the closing stages of the half.
The pattern of play remained similar in the second half as the sides battled for supremacy.
Nick Abendanon did produce a real moment of quality halfway through it though as he jinked past a number of Quins tackles before chipping the ball into the in-goal area but Olly Woodburn was unable to touch it down.
And the home side made them pay for their profligacy moments later as Evans rediscovered his kicking boots to convert a penalty opportunity from the left touchline.
The Kiwi fly-half then gave his team the lead with another three points but he had his pack to thank for winning the penalty as they began to dominate more in the scrum.
Harlequins then sealed victory with just over five minutes remaining as Brown came up metres short of the line before Karl Dickson fed Maurie Fa'asavalu, who had come off the bench to make his return from injury, to crash over for the crucial score.
Bath had two chances to record a losing bonus point after Fa'asavalu gave away a penalty and was sinbinned for an illegal tackle and Joe Gray conceded a penalty for not rolling away from the tackle area.
But in the absence of Heathcote, who went off injured as a result of the Fa'asavalu challenge, Jack Cuthbert was unable to convert either kick and Bath left the Stoop empty-handed and remain in eighth place in the table.
Pens: Evans 3
Pens: Heathcote 2
Yellow cards: Marler (Quins - 30th min); Cuthbert (Bath - 66th min); Fa'asavalu (Quins - 77th min)
Harlequins: 15 Mike Brown, 14 Tom Williams, 13 George Lowe, 12 Jordan Turner-Hall, 11 Ugo Monye, 10 Nick Evans, 9 Danny Care, 8 Nick Easter, 7 Luke Wallace, 6 Tom Guest, 5 George Robson (c), 4 Olly Kohn, 3 James Johnston, 2 Joe Gray, 1 Joe Marler.
Replacements: 16 Rob Buchanan, 17 Mark Lambert, 18 Will Collier, 19 Tomas Vallejos, 20 Maurie Fa'asavalu, 21 Karl Dickson, 22 Rory Clegg, 23 Ross Chisholm.
Bath: 15 Nick Abendanon, 14 Olly Woodburn, 13 Matt Carraro, 12 Olly Barkley, 11 Tom Biggs, 10 Tom Heathcote, 9 Michael Claassens, 8 Simon Taylor, 7 Francois Louw (c), 6 Carl Fearns, 5 Ryan Caldwell, 4 Dave Attwood, 3 David Wilson, 2 Pieter Dixon, 1 Nathan Catt.
Replacements: 16 Ross Batty, 17 Charlie Beech, 18 Kane Palma-Newport, 19 Ben Skirving, 20 Guy Mercer, 21 Mark McMillan, 22 Dan Hipkiss, 23 Jack Cuthbert.
Venue: Twickenham Stoop
Referee: Wayne Barnes