Harlequins celebrated 50 years at their Twickenham Stoop ground with a 27-19 win over Gloucester as the visitors could not overcome the decisive loss of three men to the sin-bin.
In a highly entertaining game, Gloucester were firmly in contention for the first half-hour but the sin-binning of their scrum half, Jimmy Cowan saw the game turn dramatically in favour of the Quins.
Two penalties from Nick Evans to a try from Billy Twelvetrees saw Quins hold a 6-5 lead but two converted tries from Nick Easter and Danny Care in the absence of Cowan saw the hosts take control.
But that was not the end of Gloucester's woes as Tom Savage and Martyn Thomas were both yellow carded early in the second half to ensure there was to be no comeback from the visitors.
Luke Wallace and Jonny May exchanged tries as Gloucester battled to the end. The visitors being helped by the Quins losing George Robson to the sin-bin and were rewarded with a second try from Twelvetrees.
Gloucester were able to include both their England players in Twelvetrees and Ben Morgan. Matt Kvesic and James Hudson were recalled to the pack with Charlie Sharples and May occupying the wing positions.
Chris Robshaw was an absentee for the Quins but Mike Brown, Care and Joe Marler were all in their starting line-up.
Straight from the kick off, Gloucester were penalised and fell behind to a penalty from Nick Evans.
A careless error from Care then gave Gloucester their first chance. The scrum half threw the ball back into his own 22 from where Brown kicked directly into touch to concede a line-out. The visitors secured possession to capitalise when hooker Huia Edmonds threw a delightful dummy to send Twelvetrees over for the try which Freddie Burns failed to convert.
Evans put Quins back in front with his second penalty and they held that 6-5 advantage at the end of a very open first quarter as both sides tried to run the ball at every opportunity.
Gloucester were having marginally the better of the half in terms of possession and territory before they suffered two crucial blows in quick succession. First Cowan was yellow-carded for deliberately impeding Care as the Quins scrum half chased his own kick ahead before Easter drove over from a close range line-out for a try which Evans converted.
Worse was to follow for the visitors as Burns' restart went straight into touch to put his side on the back foot once again. Quins were soon back in the opposition 22 and over the try line when Care saw a gap and darted over for Evans to convert.
Cowan's absence had seen Gloucester concede 14 points , but he returned in time to see Burns miss with a straight-forward penalty to leave Gloucester trailing 20-5 at the interval.
Within three minutes of the restart, Gloucester were back down to 14 men as their captain, Savage was yellow-carded for taking down Robson in the line-out. Evans kicked for the corner, Wallace drove over, Evans converted and the game was up for Gloucester.
Half-time replacement, Thomas, became Gloucester's third player to be sent to the bin but it was they who scored the next try as Quins became careless with their handling. Jonny May took advantage to seize the loose ball and run 50 metres to score a try which Burns converted.
Robson became Quins' first occupant of the sin-bin for off-side at a ruck and the home side looked to have extended their lead when Tom Williams crossed the line but the TMO ruled that the final pass from Evans to Williams was forward.
With 13 minutes remaining both teams were restored to 15 players and it was Gloucester who finished the stronger to gain reward with a late try from Twelvetrees, who collected a clever chip through from Burns before Evans got back to foil May as the flying wing nearly secured the visitors a deserved bonus point.