It was a far from vintage performance from the Saints but it was convincing enough against a dogged but poor Edinburgh side, who never looked like threatening Saints’ unbeaten European record.

The game was a very uninspiring affair up until the last eight minutes when Saints scored three tries all from excellent wing, Paul Diggin, who finished with a total of four.

Northampton had the better of the opening exchanges and it came as no surprise when they took a fifth-minute lead.

Stephen Myler declined to kick for goal when a penalty was awarded choosing the option of a kick to the corner.

Saints won the lineout and drove forward with Brian Mujati being awarded the try following confirmation from the video referee with Myler converting it.

Edinburgh responded immediately with some good attacking play with Tim Visser running strongly past Joe Ansbro on two occasions but Chris Paterson was unable to give them reward when he missed a 45-metre penalty attempt.

A poor pass from Ross Rennie allowed Northampton to get back into their stride and Myler made no mistake with a straightforward penalty to give the Saints a 10-point lead after 15 minutes.

The Saints continued to be the dominant side and extended their lead on the half-hour.

Jon Clarke and James Downey, the Northampton centres, combined cleverly to threaten the visitors’ defence before a neat kick ahead by Myler was expertly picked up by Paul Diggin for a try, again confirmed by the video referee, which Myler was unable to convert.

When Edinburgh secured possession they moved the ball sweetly but their attacks broke down at crucial moments and they were dealt a blow when Paterson left the field with an injury.

This resulted in David Blair taking over as goal kicker and his first penalty attempt was a poor one, with his weak kick from 30 metres sailing wide.

Just before half-time Edinburgh received another setback when prop Kyle Traynor was yellow carded following a melee between a few players.

However Myler’s long-range penalty attempt fell short to leave the Saints 15-0 ahead at the interval.

Edinburgh offended straight from the restart and this time Myler made no mistake with a 40-metre kick but the Saints could not take any further advantage from Traynor’s spell in the sin bin.

The prop’s return gave the Scots renewed hope and they enjoyed their best spell of the match in terms of territory and possession but they failed to threaten the Northampton line.

Influential forwards Dylan Hartley and Mujati were replaced on the hour indicating that the Saints considered the job done with the game deteriorating rapidly as both sides made a huge amount of unforced errors.

There were frequent turnovers as both sides struggled to bring any continuity to their play.

At long last with eight minutes Northampton got their third try when, following another handling breakdown by the visitors, Diggin was put in the clear to race 50 metres to score.

And in the last two minutes there were two more for the wing as he supported excellent running from Ben Foden and Bruce Reihana.