Substitute Felipe Contepomi came off the bench and booted Bristol to a last-gasp 28-26 victory over Saracens at Vicarage Road.

The Argentina fly-half, a 64th minute replacement for Shogun captain Jason Little, made no mistake with an 81st minute penalty to send Saracens crashing to their 15th defeat of the Zurich Premiership campaign.

It has been another season of underachievement for the London club whose outing this afternoon was to be a crucial battle against relegation until English Rugby Ltd's decision on Thursday to deny Rotherham promotion to the top flight.

And this defeat once again highlighted Saracens failings - their inability to defend a lead and an obvious lack of confidence when their backs are up against the wall.

Fly-half Luke Smith, who finished with 21 points, guided them to a 17-8 interval lead but Bristol chipped away at the deficit with tries from Brendan Daniel and Lee Best to help claim Bristol' first away league win in seven outings.

Smith had racked up 10 points as early as the 11th minute. He ran onto a flat pass from his half-back partner Kyran Bracken at a line-out before shaking off some feeble Bristol tackling to touch down under the post.

The conversion was stroked over before he added an easy penalty shortly after.

But Saracens found themselves stretched in the 14th minute when some neat link-up play between Daniel and Best saw the ball fed to winger Alex Cadwallader who raced in at the right corner.

Fly-half Matt Carrington failed to add the extras but was on target on the 19th minute with a penalty which slashed the home side's lead to 10-8.

Bristol continued to threaten and in the 24th minute they missed a glorious chance to take the lead when centre Jamie Williams neglected a clear overlap with the line beckoning.

The error proved costly just moments later when the speculative pass from Carrington was intercepted by Tom Shanklin who sprinted 50 yards for an easy try, improved by Smith.

Shanklin had to leave the field with a thigh injury after crossing and his departure prompted the arrival of Thomas Castaignede - the French stars first home appearance of the season after spending 18 months on the sideline through injury.

Saracens continued to go on the offensive and went close on two occasions as Bristol's error-strewn display continued to take its toll.

The last move of the half saw several players involved as the home side swept deep into Shoguns territory but a knock-on from Matt Cairns ended the threat.

Carrington booted a penalty six minutes after the break before he was required to convert Daniel's try - the Shoguns flier making the most of sloppy defending to canter in at the corner.

Some slick handling saw Best ghost through for a neat converted try but Smith added another three points with four minutes to go. However, Contepomi stepped up in the dying moments to deliver Bristol's winning blow.