Shanghai - World No 2 Jordan Spieth fired the round of the day, a flawless nine-under 63, to climb into contention at the World Golf Championships-HSBC Champions on Saturday in Shanghai.
The 22-year-old American had nine birdies and no bogeys to storm up the leaderboard from 27th to a share of fifth place, three shots behind leader Kevin Kisner.
Weather delays due to rain and thunder in the morning meant two players of the last three-ball group finished in almost total darkness after the 17:02 sunset time at Sheshan International Golf Club.
The third member of the group, Scotland's Russell Knox exercised his right not to tee off on 18 in the gloom and will have to come back Sunday morning to complete his third round.
Overnight leader Kevin Kisner saw his lead whittled to one stroke after a 70 took him to 16-under par.
One shot behind are Knox, the 2013 winner here Dustin Johnson and China's young Li Haotong who for the third day running showed he could compete with the cream of world golf by shooting a six-under 66.
Spieth, starting his third round 10 strokes behind Kisner, moved into contention by collecting eight birdies through 15 holes to move to 12-under par.
He missed a 15-foot eagle putt at 18th for a 62, but still signed for a nine-under 63 and a 13-under total.
Masters and US Open champion Spieth said it could have been even better as he missed four shortish birdie putts that, had they all dropped, would have seen the 22-year-old post a 59 -- an almost mythical score achieved only six times in PGA Tour history.
"I missed four putts inside eight feet today and that's not normal," Spieth said.
"So what could have been and what it was, both are special. I'm not going to complain about the round but I felt like the way I played could have been 10 or 11 (under) for sure."
Spieth said his best shot had been his approach to set up a two-foot birdie putt at the long par-four 15th.
"I loved my shot into 15," said the young Texan. "I hit just a laser six-iron right at it and it stuck."
Meanwhile local 20-year-old hero Li was off to an electrifying start for the third day running, pouring in four straight birdies including putts of 20 and 25 feet at the first and fourth before a bogey at the fifth arrested his charge.
When Li holed another 20-footer to birdie the long 603-yard eighth the roars could be heard all over the course.
Another long birdie putt at the 13th and a much shorter effort at the 15th took him to a share of second at 15-under.
Asked if he thought he could win in world-class company, Li said honestly: "I don't think so. My goal is to finish top 10."
Kisner had just 24 putts in his 66 on Friday, but little dropped Saturday until he went the direct route and chipped in at 15. He followed with a birdie at the short par four 16th to grab the clubhouse lead.
Former world number one Rory McIlroy, hit by food poisoning earlier in the week, started the day level with Spieth but his 68 left the four-time major champion eight shots off the lead.
"I gave myself a lot of chances, but again, I didn't really make anything on the greens," said McIlroy. "That 68 really felt like a 73 or a 74."
Leading scores in the clubhouse after the third round of the World
Golf Championships-HSBC Champions tournament at Sheshan International
Golf Club, Shanghai, on Saturday (par 72):
200 - Kevin Kisner (USA) 64-66-70
201 - Dustin Johnson (USA) 65-71-65, Li Haotong (CHN) 66-69-66
203 - Jordan Spieth (USA) 68-72-63, Patrick Reed (USA) 65-70-68, Ross Fisher (ENG) 69-69-65
204 - Thorbjorn Olesen (DEN) 64-74-66, Scott Hend (AUS) 68-69-67, Branden Grace (RSA) 63-71-70
205 - Bernd Wiesberger (AUT) 70-66-69, An Byeong-Hun (KOR) 69-68-68
- Marc Leishman (AUS) 69-72-65, Thongchai Jaidee (THA) 72-68-66, Sergio
Garcia (ESP) 68-70-68, Matthew Fitzpatrick (ENG) 68-69-69
207 - Henrik Stenson (SWE) 69-72-66, Steven Bowditch (AUS) 64-75-68, James Morrison (ENG) 69-70-68, Hunter Mahan (USA) 68-68-71
208 - Rickie Fowler (USA) 68-72-68, Rory McIlroy (NIR) 68-72-68, Daniel Berger (USA) 68-71-69, Harris English (USA) 67-71-70
209 - Bubba Watson (USA) 68-73-68, Charl Schwartzel (RSA) 68-72-69
210 - Louis Oosthuizen (RSA) 68-69-73
223 - Adam Scott (AUS) 75-76-72
Russell Knox (SCO, 15-under par one behind leader) has still to
complete his third round after opting not to play the 18th hole in