The Saints just about deserved the win as they were the more penetrative side but the Quins could certainly have made it a whole lot more difficult but for crucial errors and a couple of key refereeing decisions which went against them.

Williams, the man at the centre of the 'Bloodgate' incident, returned to the Quins line-up having completed his four month ban but he had little chance to impress and was replaced after 58 minutes.

Northampton were ahead within three minutes of the start. Harlequins turned the ball over on halfway and the Saints moved it swiftly for Jon Clarke to chip ahead.

It was a neat kick as both David Strettle and Chris Robshaw failed to deal with it allowing Bruce Reihana to latch onto the loose ball and score. Stephen Myler missed with the conversion attempt.

The Quins then produced a period of sustained pressure but Northampton were at their most determined in defence to keep them out.

A couple of penalties in the hosts' favour allowed the Saints respite and had Phil Dowson passed the ball when he quickly took a penalty Northampton would have extended their lead.

Myler had a chance to do just this after 19 minutes and he made no mistake by firing over a splendid penalty from inside his own half.

Some of the Saints' back play was particularly impressive with Reihana, James Downey and Chris Ashton all displaying neat touches but it was left to Myler to extend the advantage to 11 points with a 30 metre penalty after 32 minutes.

Northampton were then dealt a double blow when, on the advice of the touch judge, Neil Best was yellow-carded for an illegal challenge on Tom Guest and the resulting penalty saw Nick Evans reduce the lead with his successful kick.

Quins should have reduced the deficit even further when Nils Mordt tore the home defence apart to run 35 metres but Mike Brown's scoring pass to Williams was a shocking one and then moments later another error saw Williams once again deprived of a try when David Strettle's final pass was adjudged to be forward.

To make matters worse for the Quins they were then awarded a very kickable penalty but it was reversed for a punch by James Percival to still leave the visitors 11-3 adrift at the interval.

Myler kicked a penalty after three minutes of the restart and Best returned with no serious damage done to his side's chances.

Courtney Lawes, released by England, and Euan Murray, playing his first game of the season were both introduced by the Saints but it was the Quins who had the better of the third quarter but they failed to make any inroads into the Saints' lead.

Once again they were made to pay when Northampton broke away and Soane Tonga'uiha provided the scoring pass for Juandre Kruger to score a try which Myler failed to convert.

Despite the Saints having sealed the match, the Quins continued to press and eventually got their reward with 10 minutes to go when Josh Drauniniu crossed in the corner for Evans to land the conversion.

An exchange of tries from Tonga'uiha and Drauniniu in the closing moments ensured an exciting finish to the game.