Ross McGowan sank an eagle putt on the ninth to take a two-shot lead heading into the final nine holes at the Johnnie Walker Classic.
The 26-year-old Englishman entered the final round in a tie for first place with compatriot John Bickerton on 14 under and parred his first eight holes at The Vines Resort and Country Club to maintain his position at the top of the leaderboard.
But the 2006 English Amateur champion, who has yet to win on the European Tour, surged two shots ahead of Bickerton, Japan’s Hiroyuki Fujita and Australian Michael Sim after making eagle on the par-five ninth.
Bickerton dropped a shot after bogeying the fifth but returned to 14 under with a birdie on the ninth.
Fujita started his round on 11 under and dropped four shots behind McGowan after a bogey on the first.
But the 39-year-old, a six-time winner on the Japan Golf Tour, got back on track with birdies on the second and fifth and had moved into a tie for the lead with back-to-back birdies on the ninth and 10th.
Sim also began on 11 under and had two birdies on the front nine before nailing another on the 10th.
Paul Casey held the clubhouse lead on 13 under after firing a six-under-par 66 that included eight birdies and two bogeys.
He was joined on that mark by Lee Westwood, who began his round on nine under but birdied the first two and final two holes of the front nine to close the gap to McGowan to just one stroke.
But the former European Tour Order of Merit winner ran into big trouble when he attempted to go for the green in two on the 10th but dumped his shot into a swamp to the left.
He escaped the water but duffed his chip and took double bogey after missing a six foot putt.
However, birdies at the 11th and 13th saw him return to 13 under and a share of sixth with Casey, Dutchman Robert-Jan Derksen and New Zealand amateur Danny Lee.