Harlequins kept Northampton in trouble at the bottom of the Guinness Premiership by inflicting a fifth straight defeat at Franklin's Gardens.

Fly-half Andrew Jarvis was the Harlequins' hero - kicking three second-half penalties to wrap up his side's sixth in seven games to keep alive their play-off hopes.

But Heineken Cup quarter-finalists Saints received a welcome boost with the return of skipper Bruce Reihana. The former All Black had been sidelined with knee and hamstring injuries since September 23 and started at full-back.

Quins had also been in trouble at the bottom before a run of five straight wins lifted them up the table.

That run came to an end in a previous game at Bath and Quins were aiming to complete a double over Saints having grabbed their first Premiership win this season against them in November.

But they had not won in Northampton for almost a decade and suffered a setback inside the opening two minutes when Stuart Abbott had to be replaced after a collision.

Quins still went ahead in the fourth minute when scrum-half Andy Gomarsall charge down Carlos Spencer's kick to cross and Adrian Jarvis added the extras.

Jarvis missed a 10th-minute penalty and Northampton struggled to find a way back. They looked bereft of confidence having scored only 45 points in their previous five Premiership games and lost possession on the three occasions they got deep into Quins territory inside the opening quarter.

Tempers reached boiling point midway through the first half when Saints lock Christian Short and Quins skipper Paul Volley were yellow carded for fighting.

Saints winger Ben Cohen then appeared to push over one of the touch judges during another clash near the touchline before Northampton claimed their first points after 27 minutes when number eight Paul Tupai was driven over in the corner after a five metre line-out.

Spencer missed the conversion and that meant Quins led 7-5 at the break.

Saints got the second-half off to the perfect start. Cohen beat David Strettle to Jarvis' re-start and set off on a rampaging run down the middle of the pitch. He shrugged off the attentions of Ugo Monye to crash over between the posts. Reihana added a conversion to put Saints in front 12-7 but the joy was short-lived.

Quins got the ball wide soon after the re-start and Strettle side-stepped Cohen to cross in the corner for his seventh try of the season after 46 minutes.

Jarvis missed the conversion and that meant the scores remained tied at 12-12.

Saints suffered another blow when Darren Fox was yellow carded after 53 minutes as Jarvis kicked the resulting penalty.

He added another from 45 metres after 61 minutes to open up a six-point lead for the visitors that was pegged back to three by Reihana's penalty six minutes later.

Northampton then gifted the visitors chance to re-establish a six point lead. A push on volley led to a penalty that Jarvis belted over to make it 21-15 with nine minutes left.

There was no way back for Northampton from there and Steve So'oialo grabbed a third try for Quins in the dying moments. Jarvis added the conversion.