Li Haotong will head into the final round of the inaugural Saudi International powered by SBIA in a share of the lead after producing four eagles in a remarkable third-round 62 on Saturday.
After opening his round with a chip-in eagle, Li mixed two birdies with a double bogey before firing three more eagles on his back nine to catch halfway leader Dustin Johnson at the top of the leaderboard.
Johnson had found himself in possession of a four-shot lead after carding six birdies - including four in a row from the ninth - and a solitary bogey in his first 12 holes.
But with Johnson safely parring his way home and Li closing his round with back-to-back eagles, World Number Three Johnson was joined at the top on 16 under par.
The duo head into Sunday's final round five shots clear of Englishman Tom Lewis in third after he posted a bogey-free 62.
Li began the day three strokes behind Johnson but soon set about closing that gap, holing out for an eagle from the rough at the first to jump to ten under.
He picked up a shot at the fourth before a double bogey on the sixth threatened to derail his challenge.
But he did not let that affect him, bouncing back with a birdie from 18 feet at the seventh.
Li reduced Johnson's lead back to one shot after chipping in for another eagle at the tenth.
The American re-established a healthy four-shot advantage courtesy of four straight birdies from the ninth but Li produced a grandstand finish to wipe out Johnson's lead.
He launched his tee-shot at the 17th to within five feet before tapping in to make it three eagles at par-fours in a single round.
And Li finished the round by holing an eagle putt from eight feet at the last to join Johnson on 16 under.
After his round, Li said: "Very lucky today.
"Those eagles, especially the last couple of shots, were really solid but except that, honestly, my play wasn't that good.
"But I did make a lot of par putts.
"If it (the approach into the first) didn't go in the hole, it could have been off the green. It's a very lucky eagle over there.
"At the tenth, that's what I wanted to play, that way, but I felt like I pushed it a little bit. I got a lucky bounce, kicked it left and went in the hole, which is very lucky, too."
Johnson set the ball rolling with birdies at the second and fourth before dropping a shot on the fifth.
He tapped in from close range for gains at the ninth and tenth before making another at the 11th.
And the 2016 US Open Champion made it four-in-a-row after holing from 25 feet on the 12th to get to 16 under.
He created a series of chances to extend his lead but could not put another birdie on the card and was caught when Li finished with a pair of eagles.
Johnson was pleased with his performance. He said: "I thought I played well. I probably played just as well as I did yesterday.
"I gave myself a lot of opportunities and made a lot of good putts. Just holed a few more yesterday than I did today, is the only difference.
"For me, I just go out and play like I've been playing and hopefully can roll in a few more putts and see what I can do.
"Haotong is a good player. He's obviously playing well right now. I think it's going to be kind of a tough match against him tomorrow for the most part, but I'm looking forward to it."
