Harlequins "A" will face Exeter Braves, in the Aviva "A" League final, following a 17-20 victory over Northampton Wanderers at Franklin's Gardens.
A heroic defensive effort from the London side in the first half was then turned around in the second half as Quins enjoyed the majority of territory and possession.
Tries from Charlie Walker and Vasily Aremyev, alongside penalties from Rory Clegg and Greig Tonks had the scores tied at 10-10 at the break.
However, the boot of Clegg and a penalty try for Quins in the second half ensured the visitors a victory to set up the final next Monday evening.
The Wanderers opened the scoring after just five minutes when the home side worked their way up field with numerous surges from the forwards. When the Wanderers made it to the 22 metre line, the ball was shipped wide. Artemyev took an inside line from the centres and the fullback ran in untouched to score. The conversion was added and the home side lead 7-0.
Clegg got Quins on the score board through the boot and moments later, the fly-half was lining up a conversion as a result of a Charlie Walker try. With the Wanderers in possession and looking threatening, Tonks threw a wide lofting pass in midfield. Walker intercepted the pass and the winger ran in from the halfway line. With the conversion from Clegg, Quins lead 7-10.
Tonks slotted his first penalty on 15 minutes to bring the scores level. For the rest of the half, the Wanderers launched wave after wave of attack in the Quins half, but the defence stayed strong to give the home side nothing.
Aremyev looked to have made a second score when he crossed over in the closing stages of the half. However, in the act of scoring the Wanderers full-back knocked on as a result of heavy pressure from the Quins defence.
In the second half, Walker had a chance to add a second to his tally. Following a knock on from Northampton, the winger had a foot race with the back three and as the winger kicked the ball forward, it bounced into touch, but Quins had however gained 80 metres of territory.
Tonks had a chance to give his side the lead, but his effort on goal hit the post for a second time. Following this, Northampton worked their way back into the Quins half and when the ball was shipped wide from a Northampton lineout, Scott Armstrong crossed over to score. With the conversion, the home side lead 17-10 after 51 minutes.
With Northampton's discipline beginning to falter, Clegg added a penalty to draw the scores level again.
Quins kept the pressure and the momentum and they worked phases in Northampton's half. A sniping run from the captain, Karl Dickson, brought Quins right up to the line. Quins then won a penalty as the home side failed to release and Quins opted for a scrum.
This set piece had been dominant all game and as the hour mark passed, Quins were awarded a penalty try from referee Martin Fox. Clegg converted and Quins took a 17-20 lead.
Quins remained in possession for the closing stages of the game and looked threatening in attack. With Northampton's ill-discipline continuing, Clegg's boot kept the home side camped in Northampton's half for the remainder of the game as Quins secured their place in the Aviva "A" final.