American Kevin Stadler, the world number 256, justified tournament organisers’ decision to invite him to compete by carrying off the Johnnie Walker Classic title in Perth.
The son of 1982 Masters champion Craig Stadler eagled the 18th hole to steal ahead of Australian Nick O’Hern.
His final-day 69 followed rounds of 64, 69 and 66 and made for a 20 under par aggregate total of 268, earning Stadler a £210,000 cheque, by far the biggest prize of the 26-year-old’s fledgling career.
O’Hern had carded a closing 68 for second place, while sharing third on 16 under 272 were Australians Robert Allenby and Richard Green after final rounds of 66 and 71 respectively.
Korean KJ Choi finished with a 72 for fifth place a further shot back, while England’s Ian Poulter was in a group of three on 14-under.
Poulter carded a 69 and at one stage was only three strokes off the pace before two late bogeys cost him any chance of victory.
Another Englishman, Ross Fisher, shot a final-round 72 to finish 12 under, with Paul Casey one stroke further behind after his one-over-par fourth round.
Poulter climbs to 19th on the European Tour Order of Merit, with Fisher rising to 29th and Casey maintaining fifth place.
Stadler’s lowly world ranking meant he had to rely on an invitation into the tournament, yet he dominated it and converted his overnight lead into victory.
Amazingly, he eagled the last in the second, third and fourth rounds, with a brilliant three-iron approach presenting him with a tap-in today. That undid the damage of three successive bogeys on the front nine.
England’s Steven Webster finished nine-under overall, one stroke ahead of Ian Garbutt who picked up two strokes on the final day.
A host of Englishmen finished on seven-under, including Gary Emerson, Mark Foster, Sam Little and Oliver Wilson.
Scotland’s Simon Yates had a terrific day with a six-under 66 to finish on the same mark, but countryman Stephen Gallacher’s four-over 76 meant he slipped back to five-under.
Poulter’s sixth-place finish may have qualified him for the Accenture World Match Play Championship starting in San Diego on Wednesday week.
Poulter, who reached the semi-finals at La Costa last year and earned over £237,000, flew to Australia 67th in the world and needing to climb into the top 64.
The new rankings are released tomorrow, but with Sergio Garcia not playing at La Costa 65th will be good enough to earn a place and Poulter should have done enough.
