Rory McIlroy turned in 33 to maintain his one shot lead as the WGC-HSBC Champions got set for a thrilling finale at Sheshan International Golf Club.
The Northern Irishman made three birdies on the front nine to move to 18 under but he had an elite chasing pack breathing down his neck.
Defending champion Xander Schauffele was his nearest challenger, one ahead of 2010 Open Champion Louis Oosthuizen and three clear of England's Matthew Fitzpatrick and Mexican Abraham Ancer.
A victory for McIlroy would see him claim a hat-trick of World Golf Championships titles and join Dustin Johnson and Tiger Woods as the only players to have won three of the four events.
A 14th European Tour victory - and first since 2016 - would also see him equal Darren Clarke's record for Northern Ireland.
Overnight leader McIlroy soon had company at the top as Oosthuizen holed a 15 footer on the first and there was a three way tie when Fitzpatrick hit a stunning second to similar range on the second to set up an eagle.
Oosthuizen was just over the back of the par five in two but got up and down to move to 16 under and take the solo lead.
Schauffele also birdied the second after hitting the green in two and he was joined at 14 under by Fitzpatrick when the 25 year old failed to get up and down from a bunker on the fifth.
McIlroy joined Oosthuizen at the top of the leaderboard as he spun an approach in tight at the fifth, with playing partner Schauffele also making a birdie but giving the shot straight back on the next.
Schauffele then hit a poor second on the seventh after a big drive but holed a long putt for a birdie to get back within one.
All three of the final group laid up on the par five eighth and when they all put their approaches close for birdies, McIlroy, Oosthuizen and Schauffele were beginning to pull away.
Ancer was giving chase, however, and he made four birdies in a row from the sixth to join Fitzpatrick at 14 under.
Schauffele holed from 18 feet on the ninth to briefly join the lead but McIlroy had put his approach to six feet and he led alone as Oosthuizen surrendered a bogey after getting in trouble down the right off the tee.
Matthias Schwab was at 13 under, a shot clear of Victor Perez and Paul Waring.
