Paul Diggin grabbed a club European record four tries as Northampton Saints became the first team to book their ticket for the 2011 Heineken Cup quarter-finals as they swept aside Edinburgh 37-0 to bag top spot in Pool 1 with one round to play.

With Cardiff Blues beating Castres Olympique 14-9 in the Welsh capital the Saints’ comfortable victory, their 11th in a row in the tournament at Franklin’s Gardens, over their Scottish visitors gave them an unassailable 10 point cushion at the top.

They now travel to Castres next weekend looking for the victory that should be enough to guarantee them their first home quarter-final since they won the title way back in 2000.

But even though Diggin bagged four tries to eclipse former hat-trick heroes Matt Dawson and Ben Cohen in the club’s Heineken Cup record books it wasn’t enough to earn him the Heineken man of the match award ahead of Tongan prop Soane Tonga’uiha.

A fifth minute try from a close range line-out by Springbok prop Brain Mujati set the tone for another 80 minutes of forward domination by the English Premiership outfit. Steve Myler added the conversion and hoisted the lead to 10 points with a 16th minute penalty.

The Edinburgh defence stood firm for much of the first-half and it wasn’t until home wing Diggin squeezed out of two tackles to reach the left corner that the game’s first try came just after half-an-hour.

Edinburgh lost prop Kyle Traynor to the sin-bin on the stroke of half-time and Myler increased the lead immediately after the re-start with a penalty. At 18-0 the Saints were cruising, but they picked up the pace in the final 10 minutes when Diggin went on his one man try crusade.

His first was a length of the 22 run in to the left corner and then Joe Ansbro handed him his hat-trick by giving him the ball behind the posts five minutes later. Then Bruce Reihana made the running to give Diggin another simple run in to make it three tries in eight minutes to round off an exceptional night’s work.