An early birdie blitz from leader Bryson DeChambeau saw him take a three-shot lead into the turn on day four of the Omega Dubai Desert Classic.
The World Number Five, who is hunting his maiden European Tour title, began his final round with a one-shot advantage over defending champion Li Haotong after Saturday's 68.
But he soon set about increasing that lead, holing his birdie putt from 20 feet at the first before making another gain at the second.
He then continued his perfect start to the round with another birdie at the long third from close range to get to 19 under par.
DeChambeau continued to create chances on the front nine but had to settle for six more pars to reach the turn in 32.
Englishmen Ian Poulter and Paul Waring were the leaders in the clubhouse on 16 under, alongside the American's other nearest challenger Sergio Garcia, who made six birdies in his first 14 holes on Sunday.
Early starter Justin Harding had shown the leaders that there were low scores out there, making an eagle and seven birdies to sign for a closing 63 and finish the week on 15 under.
