|Nedbank Challenge final leaderboard|
|-18 D Willett (Eng) -14 R Fisher (Eng) -12 L Donald (Eng) -9 M Siem (Ger) Selected others: -6 M Jimenez (Spa) -1 S Gallacher (Sco) +1 T Fleetwood (Eng) +2 L Westwood (Eng), +5 T Bjorn (Swe)|
England's Danny Willett carded a final round 66 to win the Nedbank Challenge in Sun City by four shots from compatriot Ross Fisher.
Willett, 27, whose only other European Tour win came in 2012, hit six birdies and no bogeys to finish on 18-under par at the Gary Player Country Club.
He said: "We had a plan to be aggressive and to shoot low to put it out of reach, and it happened."
Overnight leader Luke Donald slumped to a one-over 73 to finish in third.
Willett trailed Donald by one heading into the final round, but had overtaken his compatriot by the fifth whole when Donald made his second bogey of the round after a wayward tee shot.
Willett pounced with his third birdie of the day to move ahead and he led to the end.
His rivals had a glimpse of hope when he missed the green at the 14th, leaving himself with a tricky chip over a bunker back to the hole. But the former top-ranked European amateur recovered so well he still made birdie, and Fisher and Donald saw their hopes slip away.
Willett entered the tournament ranked 82, but shoots to the top of the new European Order of Merit standings.
Despite a string of top 10 finishes, his only previous European Tour win was the BMW International Open in Cologne.
He added: "You always hope to come down the last with a few shots to spare and this was unbelievable. The other time I won I was in a five-man play-off."
Behind Donald, Germany's Marcel Siem was alone in fourth on 9 under, Thailand's Kiradech Aphibarnrat was fifth and Spanish veteran Miguel Angel Jimenez completed a solid weekend with back-to-back 69s for sixth.
Defending champion Thomas Bjorn had a final round 73 to finish five-over with two-time winner Lee Westwood carding a 70 to finish two-over.