Harlequins just about held off a storming comeback from Bath to earn a 40-36 victory that lifted them back into the play-off places in the Gallagher Premiership.
With England fly-half Marcus Smith pulling the strings, and scoring one of the hosts' six tries, it looked as though Quins were going to bounce back from last week's thrashing at Saracens emphatically.
They have climbed to fourth but were made to sweat by Bath scoring 33 unanswered points in the last half-an-hour that allowed them to leapfrog Sarries to go second in the table.
Harlequins opened the scoring inside three minutes when Danny Care, in his first game since announcing his retirement from international rugby, sent Andre Esterhuizen through to score.
Smith added the simple conversion before Finn Russell's penalty put Bath on the board, only for his opposite number to come up with a typical moment of individual excellence.
After receiving the ball from Care, Smith chipped it over the Bath defence before dashing into the space in behind to dot it down himself.
Quins were dominating proceedings and had their third try in the 24th minute when a big overlap on the right led to Will Evans feeding Tyrone Green, whose pass sent Italy winger Louis Lynagh in at the corner.
The bonus point was in the bag for the hosts with half-an-hour played when a catch-and-drive from a line-out led to Alex Dombrandt grounding the ball.
A fantastic first-half performance from Harlequins was then rounded off when slick hands from the irrepressible Smith and Lynagh sent Dombrandt into space on the left, with the latter's unselfish pass giving Evans an easy finish.
The half-time break did nothing to slow Quins down, with Lynagh breaking clear before passing to Oscar Beard, who sent midfielder partner Esterhuizen clear for his second try on his 30th birthday.
Smith's latest conversion took the score out to 40-3 before an extraordinary fightback from Bath began when Will Muir managed to squeeze in down the left, despite the attentions of Lynagh and Green.
The visitors pulled another score back when Russell did superbly to get an offload away for Alfie Barbeary, who bumped off Dombrandt to score, with Harlequins' Irne Herbst sin-binned in the aftermath.
Louis Schreuder then went over from Jacques du Plessis' popped pass before Lynagh saw yellow for deliberately knocking Orlando Bailey's pass intended for Ollie Lawrence forward.
Bath then quickly scored their bonus-point try when quick hands by Schreuder, Bailey and Matt Gallagher led to Ruaridh McConnochie scurrying clear.
With four minutes left, the visitors pulled themselves to within four points when McConnochie's pass put Elliott Stooke in at the corner for a converted try, but they had to settle for the two bonus points in the end.
