Jon Rahm, chasing the world number one ranking, birdied four of the last six holes to seize a four-stroke lead after Saturday's third round of the US PGA Memorial tournament.
The 25-year-old Spaniard birdied four holes in a row starting at the 13th, surging while Tony Finau stumbled from the lead on the back nine, to take command after 54 holes at Muirfield Village in Dublin, Ohio.
Rahm, whose most recent victory came at the European Tour's November season finale in Dubai, fired a four-under par 68 to stand on 12-under 204 with Americans Finau and Ryan Palmer sharing second on 208 after 73s.
"I was perfectly happy making pars," Rahm said. "When I had that in mind, once I made it through 12, I thought 13, 14, 15 are holes you can attack if you put it in the right spot."
Rahm can overtake Rory McIlroy and claim the world number one ranking for the first time on Sunday by converting a 54-hole lead into victory for the first time or placing second.
With a win, Rahm needs McIlroy to finish worse than a two-way share of second. If Rahm is alone in second, he needs McIlroy outside the top 30 and Justin Thomas not to win.
"The number one key thing is nothing 'special' -- 100% commitment to every shot I hit. That's what I need to keep doing. If I do that I'll be in good shape tomorrow," Rahm said.
"If my short game is that good tomorrow, I can keep it good tee to green and make it a good walk down 18."
The Jack Nicklaus-hosted event is the sixth tournament since the US PGA Tour resumed following a three-month hiatus due to the COVID-19 pandemic, all events played without spectators.
Finau and Palmer shared the 36-hole lead at 9-under, one ahead of Rahm.
Rahm sank a five-foot birdie putt at the par-5 seventh but found a bunker and made bogey at the par-3 eighth.
In his late charge, Rahm sank a 13-foot birdie putt at 13, dropped his approach just beyond four feet and sank the putt at 14, holed a three-foot putt at the par-5 15th and rolled in a 26-foot birdie putt at the par-3 16th.
"Sixteen was a complete bonus honestly," Rahm said. "I didn't see how anybody could hit that green. I got lucky."
- Double-bogey disaster -
Finau began the back nine with back-to-back birdies, holing an impressive 50-foot putt at the par-4 ninth and reaching the green in two at the par-5 11th to set up a tap-in birdie to reach 12-under and seize a three-stroke advantage.
Double-bogey disaster then struck Finau at the par-3 12th when he found the rough, needed two chips to reach the green and missed a 10-foot bogey putt.
Finau sent his tee shot into the water again at 14 on the way to a bogey and, after a birdie at 15, took another double bogey at 17, needing two to reach the green from a bunker.
"It was good and then it wasn't good," Finau said. "Ran into some speed bumps on the back nine. Man, this course can get you quickly.
"I'm probably pretty fortunate to be within a few shots."
Finau is a six-time PGA runner-up whose only win came at the 2016 Puerto Rico Open.
England's Danny Willett was fourth on 210 with Australia's Jason Day and Sweden's Henrik Norlander sharing fifth on 211.
Reigning Masters champion Tiger Woods, who battled back issues Friday and shot 76 to barely make the cut, fired 71 to stand on 218.
Spain's Jon Rahm seized a four-stroke lead after Saturday's third round of the US PGA Tour's Memorial tournament