Ludvig Åberg will take a two-shot lead into the final round of the Genesis Scottish Open but Robert MacIntyre will be breathing down his neck in search of an emotional home win.
Åberg started the day with a one-shot advantage at The Renaissance Club but trailed MacIntyre by two on the back nine as the Scot carded a 63 to delight the local fans and catapult himself up the leaderboard.
The Swede then birdied the 16th and 17th, however, to sign for a 65 and get to 17 under as he searches for a first Rolex Series victory.
Australian Adam Scott carded a 64 alongside MacIntyre to sit at 14 under, a shot clear of American duo Collin Morikawa and Sahith Theegala, South Korea's Sungjae Im and Frenchman Antoine Rozner.
The home fans will be rooting for MacIntyre after he was denied victory last year by a birdie-birdie finish capped by a stunning second into the last from Rory McIlroy but Ryder Cup team-mate Åberg has looked unlikely to stumble in rounds of 64-64-65 so far.
He missed the cut at this event 12 months ago in just his fifth professional start but arrived in East Lothian this year as a DP World Tour, PGA TOUR and Ryder Cup winner and fourth on the Official World Golf Ranking.
A Rolex Series victory would be another milestone in his remarkable rise and he is relishing facing the pressure of a vociferous home crowd and a world-class chasing pack.
"It will be fun," he said. "Looks like I'm playing with Bob as well, so it will be a cool pairing and looking forward to it.
"It's fun to have an opportunity to win a golf tournament, especially at a classic place here in Scotland."
He added: "I like looking at leaderboards. I think it's important to know where you're standing and I did that today and I saw some really good scores early on.
"It makes you hungry and it makes you stay on the front foot and be aggressive and I felt like I did that well today.
"Not the most stress-free golf but it was again a good score. I'm pleased with the way I hung in there and finished it out."
MacIntyre got off to a rapid start, getting up and down at the par-five third, hitting a stunner to tap-in range at the next and eagling the par-four fifth from 43 feet after driving the green.
There was soon a three-way tie as playing partner Scott left himself just three feet at the par-four sixth having already hit stunning approaches into the second and fourth and driven the fifth but they were soon trailing Åberg after the overnight leader birdied the first from seven feet.
Åberg and MacIntyre then went blow-for-blow over the rest of the afternoon, with McIntyre holing from nine feet at the seventh before Åberg made a smart up-and-down at the third.
MacIntyre made a tidy up-and-down of his own on the tenth and put an approach to five feet at the 11th to lead on his own but Åberg put a wonderful tee-shot to three feet at the sixth to join him at 15 under.
A MacIntyre three-putt at the 12th was followed by a bounceback birdie on the 15th from 15 feet and the battle continued as Åberg got up and down on the tenth and MacIntyre made a two-putt gain on the par-five 16th.
Åberg bogeys on the 11th and 12th then put MacIntyre two ahead but the 27-year-old bogeyed the last and Åberg holed a 23-footer on the 13th, got up and down on the 16th and put a tee-shot to ten feet at the par-three next to move back ahead.
Scott could not quite keep pace with the leading duo but added a further three birdies and a bogey on the back nine to stay right in contention.
Theegala shared the lead twice as he carded an eagle and four birdies but surrendered a bogey-bogey finish in a 66, a score matched by Morikawa who carded six birdies and two bogeys.
A hole-out eagle from 189 yards at the par-four seventh was the highlight of Rozner's 68, while Im carded a 67 containing five birdies and two bogeys.
Northern Irishman McIlroy was then five shots off the lead after a 67 alongside Italian Matteo Manassero and South Africa's Erik van Rooyen.