Jason Day is within sight of his first PGA Tour victory in five years after Scottie Scheffler opened the door for his rivals at the AT&T Byron Nelson in Texas.
Australia's former world No.1 Day will enter the final round two shots off the pace in a tie for fifth after carding a five-under-par 66 at TPC Craig Ranch on Saturday.
Little-known American Austin Eckroat rocketed into a share of the lead at 16 under with a third-round 63 featuring 10 birdies and a double-bogey on the par-3 seventh hole.
China-born Zecheng Dou, who lives seven minutes from the course and is also chasing a maiden PGA Tour win, fired a 64 to join Eckroat and Dallas native Ryan Palmer (68) at the top of the leaderboard.
But heavyweights Day and Scheffler are breathing down their necks.
Scheffler started the third round expected to run away with the trophy and return to world No.1 on Monday but misfired with a ho-hum even-par 71.
He teed off five shots in front of Day but that advantage was eaten away in the first five holes.
Day birdied the second, third and fifth holes as Scheffler recorded back-to-back bogeys on numbers three and four.
Three hours later, Scheffler remained in a pack of 48 players within seven shots of the lead entering championship Sunday.
After a final-round collapse at the Masters, then missing the halfway cut at last week's Wells Fargo Championship, Day appears to be over the vertigo issues that cruelled his chances at Augusta National.
He has been knocking on the door all year, posting six top-10 finishes and eight consecutive top-20s before the Masters.
Day hasn't won on the PGA Tour since edging out Palmer and Alex Noren in a sudden-death playoff at the 2018 Farmers Insurance Open.
The 35-year-old said it never gets easier on Sundays and predicted he'd need a 66 and a 20-under total to seal the deal.
"You can't control what a guy is going to go out there and shoot tomorrow," Day said.
"But you can control your attitude and your emotions and just keep pushing along and hopefully if you give yourself somewhere around the lead on the back nine on a Sunday, you never know what happens.
"That's kind of the plan for tomorrow. Try and get myself into contention and see how it goes on the back side."
He's not the only Australian in the mix.
Fresh off his first top-10 of the year last week, Adam Scott's third-round 68 pushed him to 11 under and within five strokes of the leaders in a tie for 15th with countryman Aaron Baddeley (66).
David Micheluzzi is joint 49th on his PGA Tour debut after climbing the leaderboard to eight under with a Saturday 67.
