It was a procession in the end as a sorry-looking Bristol struggled to cope with wave after wave of Northampton attacks.

The Saints scored 10 tries – they could have had more – to condemn Richard Hill to his worst defeat as Bristol head coach in this European Challenge Cup pool clash.

Bristol lost 68-15 to Worcester in April 2004 – but at least that team didn't throw in the towel, and scored two consolation tries.

Hill included one player, centre Luke Eves, from the side that had lost 18-13 to London Irish in the Guinness Premiership in the previous match and he was not 100 per cent fit because a cut on his leg had become infected.

But, without singling out individual players other than saying "primarily backs out wide", the Bristol boss blamed a lack of effort for this embarrassing defeat.

He said: "We have been to Scarlets and Toulon and competed better than that. There were two or three characters that let the side down very badly.

"Looking at it with the naked eye, there were 12 players who played their hearts out.

"When you play Northampton you need 15 players who are committed and need to do the basics right.

"There were people making absolutely ridiculous defensive decisions. It was inexplicable.

"I was thinking about fielding the same side next weekend (at home to Northampton on Sunday) but I will have to think about that again."

Bristol didn't heed the warning signs before Northampton crossed the whitewash for the first time on 11 minutes through right wing Paul Diggin. Fly-half Stephen Myler converted.

The ball had flown into touch from one move after centre Chris Mayor had knocked on with a three-on-one overlap outside him.

This wasn't complicated rugby – it was pretty simple, with the Saints drawing in defenders with straight hands, the odd loop, or with the fliers coming off their wings to create overlaps.

Bristol were perplexed, left huge gaps and were taught a lesson of simple back play which was done with excellent precision and skill.

Skipper Matt Salter's needless sin-binning on 17 minutes didn't help, the flanker deciding to block Diggin when the winger was chasing through his own kick.

A minute later, Saints crossed for their second try. A pushover try didn't work as the ball squirted out of the scrum, but No 8 Roger Wilson picked up and crashed over. Myler added the extras.

Fly-half Adrian Jarvis replied with a penalty, but Bristol lost the industrious flanker Redford Pennycook after he put his head in the wrong place and was knocked out when trying to tackle England hooker Dylan Hartley. Pennycook bravely carried on until being replaced during the break. Bristol's other young forwards also had mixed matches. No 8 James Phillips carried well but looked ponderous and gave away needless penalties.

Second row Dave Attwood also looked good with ball in hand but needs to start playing regularly if he is to make it in the Premiership.

The Bristol defence parted a minute before Salter's return when full-back Bruce Reihana exposed hooker Scott Linklater's lack of pace and passed for flanker Mark Easter to go over. Myler again converted.

The Saints made sure of the bonus point on the stroke of half-time when, after progressing following a poor kick chase by Bristol, Diggin passed off the deck for wing Chris Ashton to score. Myler converted for a 28-3 lead.

Reihana crossed for try number five with Luke Eves hanging onto his bootlaces, Myler converting before making way for former All Black Carlos Spencer.

With Reihana enjoying himself in the open, the last thing Bristol wanted to see was Spencer.

Bristol were struggling to live with their hosts but the Kiwi took Saints to another level.

The visitors tried to clear their lines but they were helpless to prevent the onslaught.

Northampton added five tries in 15 minutes and they looked like scoring whenever they had the ball.

Prop Soane Tonga'uiha was pulled down a metre short but the ball was fired out wide by Spencer for Ashton to dive over. Spencer converted.

On 67 minutes, Reihana coasted through and passed for replacement second row Alex Rae to offload and send in Diggin for his second try. Spencer again added the extras. It was too easy for Northampton. Replacement centre Jon Clarke, Ashton and Easter all touched down in the final 10 minutes.

Spencer could have added to Bristol's misery and condemned them to conceding 70 points, but he landed the difficult conversion and missed two simple chances, as Hill's men were left 66-3 down.

Northampton: B Reihana (capt); C Ashton, C Mayor, J Downey (J Clarke 62), P Diggin; S Myler (C Spencer 53), L Dickson; S Tonga'uiha, D Hartley (P Shields 69), E Murray (B Stewart 41), I Fernandez Lobbe (A Rae 53), C Day, M Easter, S Gray, R Wilson (M Hopley 53). Rep not used: B Foden.

Scorers – Tries: Ashton 3, Diggin 2, Easter 2, Wilson, Reihana, Clarke. Cons – Myler 5, Spencer 3.

Bristol: V Lilo; T Arscott, L Eves (L Robinson 62), K Maggs, A Elliott; A Jarvis (C Ashwin 67), G Beveridge (H Thomas 59), M Irish, S Linklater (D Blaney 62), P Bracken (R Hogan 67), M Sambucetti (N Budgett 62), D Attwood, M Salter (capt), R Pennycook (A To'oala 41), J Phillips.

Scorer– Pen: – Jarvis. Yellow card: Salter (17, blocking)

Referee: R Poite (France). Att: 12, 607