Matthew Fitzpatrick will take a one shot lead into the weekend at the WGC-HSBC Champions but he will have World Number Two Rory McIlroy breathing down his neck at Sheshan International Golf Club.
Both men carded rounds of 67 on day two in Shanghai, with Fitzpatrick moving to 11 under and leading the way by one from his 2016 Ryder Cup team-mate.
Defending champion Xander Schauffele, South Korean Sungjae Im and Australian Adam Scott were then at nine under, a shot clear of local hero Li Haotong and Frenchman Victor Perez.
Fitzpatrick is looking to extend an impressive record of having won in every season since he graduated from the Qualifying School in 2014.
He has four second places on the 2019 Race to Dubai and a victory on Sunday would be his first in a World Golf Championships event.
"I've been fortunate enough to be in this position a few times already this year," he said. "A little bit different being a WGC. It means a little bit more to everyone.
"Still the same plan. Still trying to hit fairways and greens and really that's the key around here - if you keep it out of the rough, you've got a good chance."
McIlroy has finished second seven times since his last European Tour victory in 2016 and was happy not to be playing catch up heading into the weekend.
"Delighted with the first two rounds," he said. "To put myself right in contention going into the weekend is something that I wanted to do.
"It's something that I haven't done a lot of over the last few weeks. I've sort of had bad starts and then clawed my way back into a good position at the end but to be right in the tournament after two days, I'm excited."
Fitzpatrick got within one of overnight leader Li from five feet at the third but then went on a run of eight pars as McIlroy and Im did battle.
A spun approach to close range at the third brought a first birdie of the day for McIlroy and a long putt on the fourth had him within one of the lead.
Li found water on the sixth for a bogey and there was a five way tie for the lead but McIlroy soon burst out of it.
He made an eight foot left to righter on the fifth and the putt on the next went the other way from 12 feet to move him two ahead.
The Northern Irishman soon had company at the top, however, as Im started his round with three birdies to also get to nine under.
Im's hot start continued with a 12 footer for four in a row and he led by two as McIlroy found the rough off the tee at the very difficult ninth and dropped a first shot of the day.
Im found water on the sixth for a bogey but bounced back from 12 feet on the seventh as Fitzpatrick made his run on the back nine.
The 25-year-old holed an eight footer on the 12th and a long right to lefter on the next to move into solo second, and McIlroy joined him from eight feet on the 13th.
An Im bogey on the 11th meant there was a three way tie at the top but McIlroy dropped a shot on the 16th after taking three off the tee and Fitzpatrick led alone as he put a tee shot to ten feet at the 17th.
Im joined him with a stunning approach to the 13th but Fitzpatrick took advantage of the par five last from 12 feet before McIlroy put a remarkable second to two feet for a closing eagle.
Im bogeyed the 17th to fall back alongside Schauffele, who turned in 37 but then picked up shots on the tenth, 14th, 16th and last.
Scott made a hat-trick of birdies from the 13th after turning in level par, while Li took 72 blows and Perez went one better.
South Africa's Louis Oosthuizen was at seven under, one clear of Austrian Matthias Schwab and England's Paul Waring.
