Nigel Davies' side had overcome several obstacles throughout the 80 minutes, some admittedly of their own making.
Gloucester arguably were on the rough end of the referring decisions throughout, had two men yellow carded and also conceded three relatively soft tries, two in a crucial period just before half time.
Yet still they fought. One characteristic of this team has been a bloody-minded doggedness not to throw in the towel, and this quality was in evidence in spades at the Stoop.
The boot of Freddie Burns kept the scoreboard ticking over, and his side in the game as Quins tried to stretch away. Yet it was the defensive effort that was the real star of the show.
In fact, trailing 28-18 with just a couple of minutes to go, Gloucester seemed to be only in a position to deny Quins a fourth try.
But somehow, they repelled the advances of the home team and moved downfield to create the chance for Twelvetrees to score.
Not even the most ardent home fan would have denied Gloucester the losing bonus point!
The afternoon started brightly as Gloucester opened up in a really positive vein, moving the ball confidently left and right, but the home defence stood up well and pounced when ruck ball was left unguarded.
However, the home side had the first chance of points as Gloucester conceded penalties at a set scrum and then a rolling maul. The returning Nick Evans needed no second invitation to give his team a 3-0 lead.
The lead didn't last long as the Gloucester front row forced a penalty at the next scrum and Freddie Burns, the Aviva Premiership's top points scorer coming into the weekend, levelled matters.
Gloucester's defence had looked rock solid but they were then undone, frustratingly, by a Quins error.
An overthrown lineout found Fa'asavalu who powered into the 22. Quick ball created an overlap on the left and Mike Brown fought his way to the line. Evans converted for 10-3.
Gloucester could feel slightly hard done by, but responded well as Burns added his second penalty to narrow the gap after 18 minutes of play.
The home team were looking to put pace on the game but almost paid a high price for their own ambition, when a quick lineout only found Huia Edmonds whose kick moved play downfield.
It was a good spell for the Cherry and Whites, and Burns third penalty on 26 minutes, after another fine scrum, got his team back to within a point at 10-9.
It was a big ten minutes as half time approached and some serious work in defence followed as Quins came back hard.
But Gloucester struck next as Burns took a quick tap, punted downfield and then tackled the covering Sam Smith who held on to the ball illegally. Burns slotted the penalty for a 12-10 lead.
The good work was immediately undone though. A quick tap on halfway caught the retreating defence unawares and Tom Williams sucked in the defence with a dummy to put Matt Hopper over in the corner, and restore the home team's advantage at 15-12.
The Cherry and Whites looked to hit straight back before half time. However, as a good opportunity was fashioned, Sam Smith intercepted Martyn Thomas' intended pass to Shane Monahan and ran it back all the way. Evans added the extras.
The final few minutes of the half were harsh on Gloucester who were, in no shape or form, second best. In fact, Burns nudging them into the lead at 12-10 seemed a fair reflection of the play to that point.
However, you switch off for a minute in the Aviva Premiership and you get punished, and Quins pounced like the champions they are as half time approached.
It was a double body blow for Gloucester and how they responded would determine the outcome of this game.
More bad news followed during the interval, when James Simpson-Daniel, one of the game's most potent attacking weapons, was replaced by Rob Cook.
Gloucester were first to score though as Quins were penalised for obstruction and Burns landed his fifth penalty of the game, only for Shane Monahan to promptly see yellow as he took a man out in the air.
With a man advantage, Quins predictably looked to move the ball wide and exploit the gaps.
It was going to be a big effort to keep them at bay and the pack showed the way with a massive scrummage effort just metres from their own line.
Despite the valiant defensive effort, it seemed that something had to give, but Evans was uncharacteristically wide with a 56th minute penalty attempt as Gloucester took out a lineout jumper illegally.
Monahan returned to restore parity of numbers but Gloucester were immediately penalised for slipping their bind at a scrum and Evans wasn't going to miss twice in a row. 25-15 after 60 minutes.
Gloucester had their own dead-eye marksman in the shape of Burns though and his sixth penalty immediately got Gloucester back to within seven points and keep hope alive.
Inspirational skipper Mike Tindall very nearly opened up the home defence, but a knock on killed the chance, and play then swept to the other end of the field as Mark Lambert produced a bullocking run to within metres of the Gloucester line.
Gloucester held out and looked to get back on the attack themselves only to be penalised again at the scrum. Evans duly made the score 28-18.
The losing bonus point was now looking unlikely for Gloucester but Quins were still after a try scoring bonus point and poured forward looking for it. Defending desperately and killing the ball, Ben Morgan was yellow carded.
Just to the left of the posts, Quins went for the scrum option and Gloucester were certainly under the cosh but refused to make it easy and, incredibly, won a penalty.
The Cherry and Whites launched one last attack as Dan Robson was brave enough to tap and go.
Slick hands followed and Martyn Thomas screamed down the left wing only to be just hauled down by the cover.
The ball was switched right and Shane Monahan and Peter Buxton took play on, before Billy Twelvetrees came on a superb angle to break the line and score under the posts. Burns converted.
Even then, Gloucester sought to unleash one last attack but turned the ball over. Incredibly, after all the pressure, it was now Quins hanging on and Ben Botica thumped the ball into touch to end the game.
Gloucester duly tasted defeat for the first time since the opening day of the season but can take huge pride from the way they hung in here.
The Cherry and Whites are no pushover at the moment and will be looking to build further as they now enter LV= Cup action.
|Harlequins Score Card|
|Gloucester Rugby Score Card|