Northampton (13) 30
Tries: Diggin, Dickson, Ashton, Mayor Cons: Everitt 2 Pens: Everitt 2
Bristol (10) 17
Tries: Turner 2, Lilo Cons: Ashwin
Prop Soane Tonga'uiha puts Saints on the front foot at Franklin's Gardens
Northampton opened their EDF Energy Cup account with victory over Bristol in a match featuring five sin-binnings.
Debutant Mathew Turner scored an early brace for Bristol but tries from Paul Diggin and Lee Dickson made it 10-10.
Converted second-half tries by Chris Ashton and Chris Mayor, plus 10 points from Barry Everitt, saw Saints home despite Vungakoto Lilo's late reply.
Bristol had Kevin Maggs, Robert Sidoli and Mark Irish yellow-carded, while Saints lost Joe Gray and Ben Broster.
In the first half Bristol had lock Sidoli yellow-carded for holding on and Maggs soon followed him to the bin for not rolling away.
After the break Gray was also sin-binned and Broster and Irish followed him to the sidelines with just over 15 minutes to go.
The result means that Bristol have lost all six of their games this season, despite Turner's impressive debut.
The South Africa Under-20 international winger, who qualifies for England through an English mother, claimed his first try after just three minutes when he gathered Lee Robinson's pass before shrugging off two challenges to touch down in the left-hand corner.
And he showed a superb turn of pace for his second, beating Sean Lamont to Vunga Lilo's clever kick through.
Northampton director of rugby Jim Mallinder:
"We were a bit flat in the first half and we talked at half-time about picking up the tempo.
"It was a chance to have a look at a few players and I was very pleased with the way we played, and to get a bonus point."
Bristol boss Richard Hill:
"Things are picking up. We aren't playing terribly, but we are shooting ourselves in the foot.
"The story of our season is that we tend to let the other team score within about 15 seconds of getting the ball."
Hill on two-try debutant Mathew Turner:
"I was delighted with Mathew Turner. He has only had two training sessions with us and went on to score tries on both wings and make a try-saving tackle.
"He was spotted playing on the sevens circuit and I was told he was special, so we moved quickly."
Northampton: Diggin; Ashton, Mayor, Mordt, Lamont; Everitt, Dickson; Tonga'uiha, Shields, Stewart, Lord, Rae, Lawes, Lewitt, Milligan, Vickers.
Replacements: Greenhalgh for Mayor (78), Brake for Dickson (72), J Gray for Shields (57), Broster for Stewart (50), Vickers for Lord (63), Neale for Vickers (75).
Not Used: Cannon.
Sin Bin: J Gray (61), Broster (64).
Bristol: Lilo; Robinson, Eves, Maggs, Turner; Ashwin, Thomas, Irish, Regan, Bracken, Winters, Sidoli, Salter, R Pennycook, Grieve.
Replacements: Barden for Turner (67), Alford for Thomas (61), Blaney for Regan (57), Attwood for Winters (61), C Pennycook for Salter (75), Clarke for R Pennycook (65).
Not Used: Barnes.
Sin Bin: Sidoli (38), Maggs (47), Irish (64).
Ref: Nigel Owens (WRFU).