Julien Guerrier made two eagles in the space of three holes as his brilliant 63 saw him catch Jorge Campillo at the top of the Estrella Damm N.A. Andalucía Masters leaderboard.
France's Guerrier had already made five birdie in his first ten holes before firing a sensational second to four feet at the par-five 12th and another to nine feet at the long 14th.
Converting both putts saw Guerrier catch Campillo, who began the day with a four-shot lead, with both players heading into the final round on 19 under par at Real Club de Golf Sotogrande.
Spain's Campillo made four birdies in his 68 as he remained bogey-free for the week, with English pair Dan Brown and Jordan Smith third and fourth on 16 and 15 under respectively after matching rounds of 67.
Guerrier said after his round: “The key is the short game - it's where I made my score. I hit two great shots on the par fives and a little bit of luck as well; I was not playing exactly there but it finished well.
“It's not a sprint of a tournament, it's a marathon, so I just try to enjoy every moment.
“I just try to play my game and stay focused.”
Campillo made birdies at the second, fourth and seventh as he set about preserving his halfway lead in more perfect conditions in southern Spain.
Two eagles in three holes for Guerrier 🔥#EDAM2024 pic.twitter.com/ClAS9FGXBS
— DP World Tour (@DPWorldTour) October 19, 2024
The 38-year-old produced a superb par save at the ninth after a wayward drive landed amongst trees and he was only able to bump his approach into the back bunker.
Guerrier completed a hat-trick of gains with a 32-foot putt on the short fourth and added further gains at the fifth and tenth before his back-nine pyrotechnics saw him claim a share of the lead.
In contrast a tap-in birdie at the 12th was all Campillo had to show for his back-nine efforts despite some excellent approach shots as he found 17 of 18 greens in regulation.
Campillo said: "I played quite solid – apart from nine I hit all the other greens so it was stress-free.
“I hit some great shots coming in but I didn't make the putts. I felt I was hitting great putts so hopefully tomorrow I can make some of the putts.
“I was feeling good all day. I was pretty calm all day. I hit it quite good so that helped as well – so tomorrow I will try to do the same thing.
“It's always great to win in your home country. The weather is great this year and this golf course is beautiful so I'll try to win.”