World no. 5 DeChambeau had two straight bogeys on the seventh and eighth holes but ended the round strongly with four birdies after the turn, for a total of six on the day, to go 16-under for the tournament.
The American golfer is leading the Dubai Desert Classic after three rounds and closing in on his first victory overseas, but he is still not happy.
He is now one shot clear of defending champion, China's Li Haotong, with England's Matt Wallace and four-time major victor Ernie Els three shots off the pace in a tie for third. Unfortunately, again, I just didn't have the right sensations and proprioception over shots. "I can't express to you the words how awesome it would be to win on the European Tour".
A four-time major victor many thought was only waiting for the PGA Tour Champions let alone taking on young guns like DeChambeau sits one shot off the lead in third place.
Scott Hend, who had held second place overnight, slipped back to joint 14th on eight under with a score of 70, a position he shares with, among others, fellow Australian Wade Ormsby after his round of 69.
"Made it happen when it's necessary and hopefully I can have one more of those days and maybe even a better-ball striking day". I've been a professional for a very long time and I've got one more year before I'm 50.
"It was obviously a lot of fun to be able to finally hoist an worldwide trophy, I'm so happy about that".
"Especially under the gun with the heat of some good players coming up and playing well from behind me, I knew I needed to step on the pedal and that's what I did today", DeChambeau said.
Lucas Herbert, who led alongside DeChambeau after 36 holes, started poorly but recovered late on to sit fifth where he was in a four-way tie.
Although DeChambeau will not move up in the world rankings on the back of this win, he will close the gap on the four players above him and has his sights set on Justin Rose in top spot.
"I know even while not at my best, I can get it done", DeChambeau said. "If worst comes to worst tomorrow, I'll figure out a way".
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