Jordan Spieth has a return to world number one and a first World Golf Championship title in his sights after surging through the field with a brilliant 63 in the HSBC Champions in Shanghai.

Spieth began the day 10 shots behind halfway leader Kevin Kisner, but carded nine birdies and no bogeys to close to within three shots of his fellow American, who carded his first bogeys of the week in a third round of 70.

At 16 under par, Kisner held a one-shot lead over 2013 champion Dustin Johnson, China's Li Haotong and Scotland's Russell Knox, who chose not to play the final hole due to darkness after earlier weather delays.

The final group of Knox, Kisner and Branden Grace were asked by a tournament official on the 18th tee if they wanted to play the par five, with Grace making a birdie to finish 12 under and Kisner a par as Knox looked on.

England’s Ross Fisher played his last eight holes in five under par to card a 65 and join Spieth and his Ryder Cup partner Patrick Reed on 13 under, Reed recovering from a double bogey on the fifth to shoot 68.

Spieth had expected to be rusty after his longest lay-off for 10 years, going two weeks without touching a club after helping the United States retain the Presidents Cup in Korea last month.

That showed with 10 birdies and six bogeys in opening rounds of 68 and 72, but the FedEx Cup winner was close to his best on Saturday, even though he felt a number of good opportunities went begging.

“This will be the first and only time I would say this, but I was not expecting myself to be in this position come Sunday when the week started,” said the 22-year-old, who needs to finish in the top 13 to reclaim top spot from the absent Jason Day, whose wife is due to give birth to their second child. “I came in with very little confidence in my trust of what I’m trying to do in my swing.

“On the range (on Saturday) I found an easier way to get the club in the position I’ve wanted it to be in the whole week. It freed me up to be able to not think about impact position and just swing through the ball.

“I’ve struggled to shoot lower than two or three under on this golf course in the past couple years, but (Saturday) was the day to do it with ball in hand, very little wind and some gettable pins.

“For whatever reason (on Friday), I put some higher expectations (on myself) than what I’d said coming into this week. I shot four under the first day, figured maybe I could do that again. Yesterday’s conditions were tough and I lost a few shots because of it.

“(On Saturday) I came out knowing that it was a gettable golf course. I missed four putts inside eight feet — 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.”

Knox, who was initially seventh reserve for the event and only found out he would be making his WGC debut last Friday, believes he made the right decision not to play the 18th.

“Branden and Kevin wanted to get done, but it was awfully dark,” the 30-year-old from Inverness said. “It was into the wind and I was like, maybe I’ll just wait until the morning and see if I can catch it downwind or no wind.

“I was happy with my decision. My caddie didn’t want me to play the last and I think all in all, they (Grace and Kisner) maybe shouldn’t have but got away with a birdie and a par, so good on them.

“I’m going to have to wake up a lot earlier, starting at 7.45 and I won’t tee off again until probably 10.45. It’s going to take the best round of my life tomorrow, so I’m going to have to go for it. Pars are not going to win this tournament. I’m going to shoot at the pin.”

Like Knox, Kisner is seeking his first PGA Tour title after losing out in three play-offs this year, including to Sergio Garcia and eventual winner Rickie Fowler in the Players Championship.

“Experience always helps,” Kisner said. “Going against the best players in the game in a few of those play-offs, it’s always going to help me in building confidence. There’s so many guys within a couple shots of the lead. It’s going to be a dogfight tomorrow no matter what.”

Li lost a play-off to Kiradech Aphibarnrat in the Shenzhen International in April but played down his chances of a massively popular win on home soil on Sunday.

“This tournament is so big, it’s too big,” the 20-year-old said. “I know that on the final day a lot of people are going to be hitting a lot of birdies. But that’s why I thought that my target, my goal in this tournament would be making the top 10, because doing that will already be a highlight and a milestone for my short career.”

World number three Rory McIlroy rued a number of missed chances after a 68 which left him eight shots off the lead, but at least felt better after a severe bout of food poisoning on Tuesday.

“I was glad to be back to 100 per cent healthy and could give it my all out there. I felt like I played well from tee to green. I gave myself a lot of chances but again I didn’t really make anything on the greens. That 68 really felt like a 73 or a 74.

”I needed to go a little bit lower to give myself a chance going into (Sunday), but I’ll try to finish off the tournament with a good score and get myself into the top 10 or the top five.”

Shane Lowry carded a round of 72 to leave himself five over overall, after bogeys on the second, fifth and 10th holes.