Premiership: Harlequins 12-15 Bristol Bears - Bears hang on for brilliant win over Quins
Bristol Bears moved off the bottom of the Premiership as they clung on for a gutsy victory over Harlequins at a soaked Twickenham Stoop.
ries from Harry Thacker and Gabriel Ibitoye, either side of one from Josh Bassett, had Bristol 10 points in front at half-time.
Caden Murley cut the gap to three on the hour as Quins dominated possession and territory.
Despite being kept scoreless and losing Ibitoye to the sin-bin Bristol held on.
win, the Bears first in the Premiership since September, takes them two points above Bath while a frustrated Quins stay third after missing the chance to go second with their first loss in five games - with the top four prior to Christmas all suffering festive defeats.
re was a celebratory mood before kick-off as the home fans paid tribute to retiring prop Shaunagh Brown, who was carried from the field on the shoulders of her team-mates after Quins' 48-14 win over Bristol in the Premier 15s match before the men's game.
However, when their turn came, they made an uncertain start as they looked to capitalise on slip-ups for leaders Saracens, Sale and Gloucester - losing flanker Will Evans to a head injury assessment (HIA) inside the first minute before struggling for precision in their handling and at the line-out.
Bristol, by contrast, were lively and tidy and, after AJ MacGinty landed an early penalty, their discipline up front was rewarded when hooker Thacker drove over from a rolling maul for his seventh try in his last eight games as Quins' defence was turned one way then the other.
It was not until midway through the first period when Quins finally got a tune out of their attack. 
Andre Esterhuizen bounced off number eight Magnus Bradbury on halfway and sent Quins racing down the left and, after a combination of slick handling and clever lines, Bassett slid in the corner as the backpeddling Bears defence had no time to recover.
But just as the home side were threatening to move through the gears, Bristol struck back with a fine try of their own from Ibitoye.
former Quins winger had plenty to do as he received a long pass 10 metres out on the left, but a lightening step off the touchline back inside took out four covering Quins defenders as he burrowed over the line to restore the visitors 10-point lead at half-time.
Ibitoye then showed his defensive prowess in denying Care an early score in the second half, nudging the scrum-half's toe on to the touchline in a try-saving tackle as the number nine dived for the corner after collecting Esterhuizen's brilliant reverse offload.
Quins' head of steam couldn't be subdued for long though and they pulled to within three points with another clever score as Marchant broke the gain line inside the Bears 22 before Care's vision and perfect cross-field kick found Murphy lurking on the right to dive over.
Continuing to reject kicks at goal for ones into the corner, Quins drive to go for the win looked like paying off when Ibitoye was shown a yellow card for leading with his shoulder in tackling Esterhuizen with four minutes to go.
And in the last minute they created the match-winning chance.
Replacement Oscar Beard broke clear after a line-out into the Bears' 22 before feeding Esterhuizen, who steamed towards the line only for the South Africa centre to be brought down by MacGinty's desperate tap-tackle.
As Esterhuizen tumbled over the line, a sliding rip away from a diving Tom Whiteley prevented the try in a sensational piece of defending that sealed the points for Bristol.
Bristol director of rugby Pam Lam told BBC Radio Bristol:
"It was a gutsy second half from us. We've been working on the areas of our game we needed to around defence, chasing down and close contact stuff.
"What an unbelievable competition we have - when the bottom three teams knock off the top three teams on the same weekend.
"I'm really pleased for the coaching staff and the players. When you're bottom of the table there's a lot of pressure coming from outside.
"The way I see it we're only six or seven off the fourth place - that's why this competition's awesome. No-one's come from the bottom but the way this competition is all teams have a chance of making the top four."
Harlequins head coach Tabai Matson:
"We absolutely back our players and our captain to be really positive. In hindsight it's take the three, take the draw. Maybe exit and have another crack.
"But one of the things I love about joining this club is the positive intent. If there's an opportunity to score a try we'll go for that first.
"And so I tip my hat to the decision. Clearly it cost us, but I tip my hat."
Harlequins: David; Murley, Marchant, Esterhuizen, Bassett, Allen, Care; Marler, Walker, Louw; Hammond, Herbst, White, Evans, Dombrant.
Replacements: Head, Baxter, Kerrod, Matthews, Lawday, Gjaltema, Edwards, Beard
Bristol: Lane, Morahan, Radradra, Bedlow, Ibitoye, MacGinty, Uren; Thomas, Thacker, Lahiff, Batley, Vui, Luatua, Heenan, Bradbury.
Replacements: Kerr, Woolmore, Tyack, Stooke, Thomas, Whiteley, O'Conor, Lloyd
Referee: Karl Dickenson