Paul Dunne will take a one-shot lead into the final round of the Open de España but he will have two local favourites chasing him down at Centro Nacional de Golf.
The Irishman entered day three with a three-shot lead and fired a 68 to stay atop the leaderboard at 17 under, although a 66 from Spaniard Nacho Elvira cut his advantage as he goes in search of a second European Tour title.
World Number Four and local hero Jon Rahm was then at 15 under alongside Swede Henric Sturehed, one clear of Australian Brett Rumford and two ahead of England's Andy Sullivan.
Dunne claimed his maiden title at last season's British Masters supported by Sky Sports, while Elvira's best finish on the European Tour was a play-off loss at the 2016 Trophée Hassan II, although he does have four Challenge Tour wins.
Rahm has two Rolex Series victories under his belt from last season and will once again have huge galleries following him as he seeks a first professional victory on home soil.
Rookie Sturehed made his European Tour debut at the AfrAsia Bank Mauritius Open after coming through the Qualifying School but had not made a single cut before this week.
"It's probably the best my swing has felt, the best my body has felt like it's been moving, but I just didn't pull the shots off," said Dunne.
"There was a lot of grinding there on the back nine but I'm happy to get in with four under. Probably wouldn't have taken it at the start of the day but given the shots that I hit, I'm pretty happy with it leading into tomorrow.
"Everything feels good, the game feels great, I just didn't pick shots. I hit a few shots without having a shot in mind so that's something to work on for tomorrow. Hopefully I'll have a good day. I'm confident about tomorrow."
Rahm played a lovely chip into the first and an approach to tap-in range on the second to get within two of the leader but he was soon leapfrogged by Elvira who also made a birdie-birdie start.
Everything feels good, the game feels great. I'm confident about tomorrow - Paul Dunne
The 31 year old played the par five first in textbook fashion and the holed from nearly 30 feet on the second but he surrendered a bogey on the fourth to drop back to 11 under.
Rahm holed an 18-footer on the sixth to get within one of the lead alongside Sturehed, who made a birdie-bogey start but added further gains on the third and fifth and spun his approach to the seventh to tap-in range.
Dunne had made a quiet start but got up and down from a bunker on the fifth for a first birdie of the day and a two-shot lead, with Elvira also making a gain on the par five.
Dunne put his tee-shot on the par three sixth to five feet and while Sturehed cut the gap with a brilliant chip-in birdie on the ninth, Dunne holed a 35-footer on the seventh.
Rahm played a beautiful bunker shot on the tenth and hit a wonderful approach into the 11th for back-to-back birdies but Sturehed holed a lengthy putt to get up and down from a nasty spot on the 11th and join him two back.
An eight-footer on the tenth and another birdie on the next had Elvira at 14 under and with Sturehed and Rahm dropping shots on the 13th and 14th respectively, he was alone in second.
Dunne hit an approach to tap-in range on the 12th to get three ahead but Elvira got up and down on the 15th to trim the lead again, with a nice chip from Rahm and an excellent approach from Sturehed bringing a pair of birdies at the 15th.
The leader needed to make smart par saves on the 14th and 15th as Rahm and Sturehed both birdied the last to get to 15 under, but Elvira jumped out of that group with an excellent approach to the 16th.
Dunne found water off the tee on the 17th for a bogey but birdied the last, with Elvira also making a closing gain.
Six-time winner Rumford made six birdies and two bogeys in a 68, while Sullivan followed up his remarkable 75-63 start with a 65 containing eight birdies and a single blemish as he continued to mount a remarkable comeback.
Home favourite Jorge Campillo, England's Aaron Rai and Scot Marc Warren were at 12 under, a shot clear of defending champion Andrew Johnston, German Maximilian Kieffer, South African Jacques Kruyswijk and Scot Bradley Neil.