Tommy Fleetwood fired a 5-under-par 67 on Saturday to pull even with overnight leader Ricardo Gonzalez entering the final round of the Johnnie Walker Championship.
Gonzalez shot 70 to dip into a tie with Fleetwood at 16-under-par 200 through 54 holes. The four-time European Tour winner has held at least a share of the lead through each of the first three rounds.
"This is what you spend hours and hours practicing for, to be up there in golf tournaments," said Fleetwood, who was the youngest winner of the Challenge Tour in 2011. "I always used to watch this tournament as a kid and I love Scotland."
Fredrik Andersson Hed carded a 66 at Gleneagles and moved into solo third place at 15-under 201, two strokes ahead of Scotland's Stephen Gallacher and Bernd Wiesberger, who shot 64 and 72, respectively, to share fourth.
Fleetwood began the third round three shots off Gonzalez's pace, but the 22- year-old quickly made up the difference with a birdie-eagle start from the first.
Gonzalez opened with a bogey to briefly drop into second place, but he birdied two of his next three holes to reclaim the top spot. He remained there through the turn, adding another birdie at the ninth to reach 16-under.
Fleetwood, playing a group ahead of Gonzalez, bogeyed the par-3 sixth, but he recovered with three straight birdies from the eighth to pull even through No. 10.
Soon after, both players dropped a shot, as Fleetwood bogeyed the 12th and Gonzalez did the same at the 11th to slip to 15-under. But the former bounced back with a birdie at the 13th, grabbing a lead he would retain until the final hole.
The pair matched birdies at the 16th, then Fleetwood sent his tee shot at the par-5 18th under a tree to the right of the fairway. He was forced to punch out, and later missed a 6-foot par attempt to slip back to 16-under.
"The last hole does not really mean anything," Fleetwood said. "It's a tough hole and the way I hit my tee shot I did well to make six. I carved it into the trees and was lucky to have a chip out.
"If I hadn't, I would have had to go back 100 yards and could have taken anything up to a 10. The way I played the first 17 holes was fantastic."
Gonzalez took advantage, closing with a pair of pars to retain a share of the lead.
"I think the first two days, I hit it very well from the fairway to the flag," he said. "I'm happy to make 2-under par on that course."
NOTES: Gonzalez has four wins on the European Tour, but his last came at the 2009 SAS Masters ... Fleetwood is seeking his first win on the European Tour ... The PGA Centenary Course at The Gleneagles Hotel will host the 2014 Ryder Cup.