Scotland's Russell Knox could turn his late entry into the final World Golf Championship event of the season into a first European Tour title and a ?900,000 payday after a superb second round in Shanghai.
Knox was initially seventh reserve for the ?5.5million HSBC Champions at Sheshan International, but discovered last week he had secured a place in the 78-man field when JB Holmes withdrew.
And the 30-year-old from Inverness made the most of his good fortune by carding a flawless 65 in blustery conditions on Friday to lie two shots behind American Kevin Kisner, who added a 66 to his opening 64 and has not dropped a shot in 36 holes.
Knox found out he would be making his WGC debut while playing in the CIMB Classic in Malaysia last Friday and praised his wife Andrea for making the necessary arrangements - and also stepping in as a temporary caddie.
" My wife was a superstar and she filled out all the forms for us," said Knox, who made his Open debut at St Andrews in July after Rory McIlroy was forced to withdraw due to the ankle injury he suffered playing football with friends.
"While we were playing on Friday she took all the stuff to the Chinese embassy in Kuala Lumpur and had it processed. Then we had to wait around till Monday at 2pm to get them back and they gave us our passports.
"We flew here on Tuesday morning but my caddie didn't have proof of accommodation so he was a day behind us. So when we got here my wife caddied for me. We got a stand bag from the pro here and chucked the clubs in and played the quickest practise round ever and she complained heavily for the last nine holes!"
Asked if that would earn his wife a share of his winnings this week, Knox joked: "D on't worry, there was a nice mall across the street where she took care of herself!"
Kisner is the only player in the field not to have dropped a shot this week, despite not playing a practice round after suffering a back injury in the final round in Kuala Lumpur.
"I t's beyond my expectations," Kisner, who lost three play-offs on the PGA Tour in 2015, said of his form. "I'm making a lot of putts and that's fun keeping the round going when I miss a green. I'm looking forward to the weekend.
"Having an injury probably lowers your expectations and you play better. So probably something to learn from that."
A frustrated McIlroy, who recovered from a bout of food poisoning to card a 68 on Thursday, had come within inches of a hole-in-one on the 12th, but bogeyed the 13th after missing the green and was furious with another pulled iron shot on the short 16th, slamming his club into the bag and then barely bothering to line up a par putt from four feet, which he duly missed.
Things looked set to get even worse on the 18th when the world number three found water with his approach and had to let two more balls roll into the hazard as he took a penalty drop on a steep slope short of the green.
However, the 26-year-old pitched to four feet to save par and signed for a level-par 72 which left him four under par alongside Masters and US Open champion Jordan Spieth, who needs a top-13 finish to replace the absent Jason Day as world number one.
" I didn't play very well today. I was just a bit flat out there," McIlroy told Sky Sports 4. "I've left myself a lot to do over the weekend but hopefully I can shoot a couple of good scores and get myself back up the leaderboard.
" I wouldn't say I'm 100 per cent. I struggled to hit balls today on the range, got a few cramps in the stomach. But I took a couple of tablets and it sort of went away as I went through the round."
Overnight leader Branden Grace, who could overtake McIlroy at the top of the Race to Dubai with a win on Sunday, added a 71 to his opening 63 to lie third on 10 under par, with Patrick Reed and China's Li Haotong a shot further back.