Dustin Johnson gave the chasing pack some hope with a double-bogey on the last to reduce his lead to three shots after the third round of the WGC-HSBC Champions in Shanghai.
And Graeme McDowell is one of the chasing pack, sitting in third place, four shots behind the big-hitting American and reigning champion Ian Poulter.
Rory McIlroy is also in contention going into the final round, on -12 following a third round 67.
Despite also making a double-bogey on the 10th, Johnson stood on the 18th tee with his five-shot overnight lead in tact thanks to a front nine of 30 for the second day running and four more birdies in succession from the 13th.
However, the South Carolina man then drove into the water down the right-hand side of the par-five and found a greenside bunker with his fourth shot before eventually signing for a seven and third round of 66.
At 18 under par, Johnson leads by three from Poulter, who carded a 63, with Ryder Cup team-mate McDowell a shot further back on 14 under following a 64.
US Open champion Justin Rose, first-round leader joins McIlroy and Canada's Graham DeLaet were all on 12 under, while Germany's Martin Kaymer was 10 under after setting a new course record with a flawless 62.
Poulter, looking to become only the second player after world number one Tiger Woods to defend a WGC title, had charged up the leaderboard with five birdies in a row from the third and another on the ninth to be out in 30.
The Englishman also birdied the 10th but Johnson was producing some equally impressive figures, making five birdies in a row from the fifth to match Poulter's outward score.
However, the seven-time PGA Tour winner then made a complete mess of the 10th, coming up short of the green with his approach and then twice seeing his pitch to the green fail to get to the top of a steep slope and roll back to his feet.
His third attempt clattered into the pin and in the end Johnson did well to hole from 12 feet to limit the damage to a double-bogey six.
When Poulter then holed from 20 feet for an eagle on the 14th the gap was suddenly one shot, but Johnson responded once more with birdies on the 13th, 14th, 15th and 16th.
Poulter three-putted the 17th for his only bogey of the day but birdied the last to remain firmly in the hunt for the first prize of just over €1million.
"After 10 I wasn't too disappointed but obviously the double on the last hole hurt a little bit," Johnson told Sky Sports. "But overall I played really good again today. If you told me I would shoot six under teeing off I would have taken it, but obviously left a few shots out there.
"(This course) sets up well off the tee for me. I can hit a lot of drivers and I drove it really well again today, other than the last drive on 18. Besides that, I hit a lot of great shots, a lot of good putts so I have to come out tomorrow and do the same thing I did today."