Bath reached their first English cup final for nine years after stunning Gloucester with a sensational extra-time victory at Kingsholm.

Just when a pulsating Powergen Cup semi-final looked to be heading for a drop-goal shoot out, Bath wing Andy Williams struck gold and took Bath to Twickenham.

Welshman Williams' solo try in the final minute of extra-time, a kick and chase effort that was only awarded after referee Ashley Rowden consulted with the video referee Geoff Warren, gave Bath victory and secured an April 16 showdown with Leeds.

It will be Bath's 11th cup final and they have won the previous 10.

Gloucester, who had given their all in a blood and thunder encounter, were left crestfallen after the game went into overtime, tied at 19-19.

Bath wing Joe Maddock scored a try for the visitors, with fly-half Chris Malone kicking 14 points, but Gloucester speedster Seti Kiole's 62nd-minute touchdown, plus 14 Henry Paul points, meant the teams could not be separated at full-time.

Gloucester suffered a late blow when their Welsh international hooker Mefin Davies withdrew because of a thumb injury just seven days before unbeaten RBS 6 Nations title contenders Wales tackle Scotland at Murrayfield.

Davies was replaced in the starting line-up by Noel Curnier, with Curnier's fellow French front-row forward Olivier Azam on the bench for his first match-day involvement since undergoing shoulder surgery last October.

England wing hopeful James Simpson-Daniel started at outside centre, and number eight Adam Balding again featured as skipper, while Bath included full-back Matt Perry despite a late fitness scare as they targeted revenge for last month's Zurich Premiership defeat against their fierce West Country rivals.

Malone booted Bath into a third-minute lead, but Paul responded five minutes later after he missed a sitter from in front of the posts.

The kicking duel continued at pace, with referee Ashley Rowden quick to punish both sides' technical indiscipline, and further strikes from Malone and Paul tied up a fast and furious encounter at 6-6.

Bath though, produced the one moment of genuine class during an error-strewn opening period, and Gloucester had no answer.

Flanker Geraint Lewis, displaying superb footballing skills, broke deep into the heart of Gloucester territory and his perfectly-timed pass allowed Maddock to sprint over unchallenged.

Malone landed the touchline conversion, and despite Paul completing his penalty hat-trick, Gloucester's problems deepened when a bloodied Balding went off to be replaced by Jake Boer.

Bath centre Andrew Higgins cut the Gloucester defence wide open as half-time approached, and Gloucester could only halt them through illegal means as Curnier was sin-binned for knocking the ball out of Bath scrum-half Nick Walshe's hands.

Malone slotted the resulting penalty, but Bath's England prop Matt Stevens levelled it up at 14 players each, seeing yellow for a reckless technical infringement, and Paul's fourth successful penalty brought Gloucester back to within four points at half-time, 16-12 adrift.

Paul should have reduced the gap further on 43 minutes, yet he hit the post with an angled penalty attempt.

Bath knew it was a let-off, but they were soon on the back foot again, retreating at a rate of knots as Gloucester pieced together a thrilling passage of play that only fizzled out when wing Marcel Garvey just failed to grasp a poorly-directed pass.

Bath could not build on their first-half platform, and Gloucester punished them midway through the second period with a classic, if controversial, score.

Simpson-Daniel, for once freed in space, had Bath defenders guessing which way he would go next, and he kept his poise to put Kiole over, even though the scoring pass looked a yard forward.

Referee Rowden awarded the try, and Paul's conversion inched Gloucester ahead until Malone's fourth penalty tied the game up at 19-19, 10 minutes from time.

Malone's strike set the scene for a gripping finale, and it was a survival of the bravest - let alone fittest - as the semi-final reached its normal time crescendo.

Perry certainly cracked, spilling a steepling Paul kick in the shadow of his own posts, and conceding an attacking scrum, but Gloucester recklessly infringed and Bath escaped.

As the tension mounted, Gloucester prop Gary Powell was fortunate to avoid a yellow card for punching Bath substitute Gareth Delve, and Bath pressed as full-time beckoned, but when Paul sent a last gasp drop-goal wide, extra-time could not be avoided.

Bath wasted a glorious opportunity seven minutes in the first period of extra-time, but Perry could not gather a wild Malone pass with Gloucester's line at his mercy.

The deadlock still had not been broken entering the final 10-minute segment, but Bath came agonisingly close when Malone's 40-metre drop-goal hit the post.

Then came Williams' moment of magic, and Bath could begin the celebrations.