Bristol will appear in their first Twickenham final since 1984 when they meet either Sale or Gloucester in the final of the Zurich Championship.

It was Argentinean international fly-half Felipe Contepomi who put them there after scoring all the Shoguns points.

Victory gets Bristol the final place in next season's Heineken Cup, the first time they will have been in the competition.

Northampton have already qualified for the Heineken having finished in fifth spot but Bristol's victory means that Newcastle Falcons will be playing in the Parker Pen Shield next season.

Bristol included Ross Beattie on the bench for his first competitive game since joining from Newcastle last summer.

The Scotland number eight had hoped to kick-start his career but he has been dogged by a thigh strain after the two pre-season friendlies.

The lead changes four times in the first half in a game played on a sandy Memorial Stadium pitch bathed in glorious June sunshine.

The match was marred by whistle-happy referee Chris White who refused to let the game flow.

Northampton's former England fly-half Paul Grayson landed two penalties to one from his opposite number Contepomi before the first try of the game just before the midway point of the first half.

The Shoguns scored the first try of the game after wing Matt Carrington's break set up a ruck in front of the posts. Scrum-half Agustin Pichot gave a short pass to his Puma half back partner who went storming through to the line before adding the conversion.

Grayson added his third penalty, after a deliberate knock-on by Pichot, to reduce the arrears just before the half-hour only for Contepomi to restore the advantage a couple of minutes later with his second penalty of the game.

Five minutes before the break Saints went back in front with a try in the corner from blindside flanker Andrew Blowers. But it was Bristol who went into the break 16-14 in front after Contepomi landed his third penalty.

Bristol increased the lead shortly after the re-start as centre David Rees broke 30 metres to set up a ruck.

Pichot fed Contepomi who sliced through the last line of defence before adding the conversion.

Full back Nick Beal tried to set up another attack as he took a high clearance ball from Contepomi. Beal broke 40m cross-field only for Contepomi to knock him off his feet to earn Bristol a scrum.

Bristol were reduced to 14 men when hooker Neil McCarthy was shown the yellow card for tackling left wing Craig Moir without the ball.

Saints took advantage of the extra man to score two tries to put them back in front.

Saints' number eight Grant Seely scored the first in the right corner followed by a second from Blowers in the left corner.

Matt Carrington was denied a try 10 minutes from time as he put a foot in touch.

Northampton were then down to 14 men when centre John Leslie was yellow-carded for a professional foul and Contepomi stepped up to put Bristol back in front with his fourth penalty of the game going into the final five minutes.

Then Contepomi added another two more penalties before the final whistle to take his tally for the afternoon to 32 points and put Bristol through to a Twickenham final next Saturday against either Sale or Gloucester.

Teams:

Bristol: Best, Carrington, Rees, Little, Christophers, Contepomi, Pichot, Crompton, McCarthy, E. Bergamaschi, Archer, A. Brown, Short, Lipman, Sturnham.

Replacements: Johnstone for Crompton (40), Crompton for E. Bergamaschi (60), Sheridan for Archer (52), Nelson for Short (57).

Not Used: Beattie, Brownrigg, Blake, Cadwallader.

Sin Bin: McCarthy (56).

Tries: Contepomi 2.

Cons: Contepomi 2.

Pens: Contepomi 6.

Northampton: Beal, Brooks, Tucker, Leslie, Moir, Grayson, Malone, Morris, Thompson, Stewart, Phillips, Brouzet, Blowers, Pountney, Seely.

Replacements: Budgen for Morris (51), Hunter for Phillips (51), Soden for Brouzet (70).

Not Used: Richmond, Hyndman, Kirk, Shaw.

Sin Bin: Leslie (76).

Tries: Blowers 2, Seely.

Pens: Grayson 3.

Att: 5,292

Ref: Chris White (RFU).