Peter Uihlein carded a 4-under 68 on Sunday and claimed a 2-stroke victory at the Madeira Islands Open.
Uihlein was tied with Morten Orum Madsen entering the final hole when the latter, playing in the penultimate group, stumbled to a double-bogey 6, allowing the former to wrap up the win with a par.
It was the first professional victory for Uihlein, who finished 72 holes at 15-under 273. Madsen, meanwhile, ended with a final-round 67 at Club de Golf do Santo da Serra and tied for second place with overnight leader Mark Tullo (71).
"I'm just thrilled," said the 23-year-old American. "To do it playing well on the back nine, coming down the stretch, is sweet. I know Morten played a heck of a round and Mark played really well, so it was nice to come out on top."
Second-round leader Craig Lee shot 71 and ended alone in fourth place at 12- under, while Seve Benson (67), Richard Bland (68), Roope Kakko (68) and Rhys Davies (67) tied for fifth at minus-9.
Defending champion Ricardo Santos, the highest ranked player in the field at world No. 145, shot 69 for the second straight day and tied for 19th at 4- under.
Uihlein and Lee began the hard-fought final round one stroke off Tullo's pace, with Madsen trailing by four.
The 2010 U.S. Amateur champ Uihlein stumbled to a bogey at the first, but recovered with back-to-back birdies from the third. Still, he could only watch as his playing partner Tullo dropped his 8-iron tee shot from 201 yards into the cup at the par-3 fourth for a hole-in-one.
The jostling continued, as Tullo and Lee exchanged the lead over the course of their outward nine, with Uihlein hanging back after following a gain at the seventh with consecutive bogeys from No. 8.
Tullo failed to keep the momentum around the turn, carding two bogeys and a lone birdie over his final nine holes, as Uihlein and Madsen charged to the top.
Uihlein made his move with a hatrick of birdies from the 11th, while Madsen, playing in the penultimate group, methodically moved up the leaderboard with seven birdies and just one bogey over his opening 13 holes.
Both players birdied the 16th to reach 15-under and after pars on the next, Madsen unraveled on the tournament's 72nd hole.
The 25-year-old landed beside a tree off the tee, played out from there and promptly found a bunker with his third. He then sailed his fourth over the green, eventually settling for a double-bogey, allowing Uihlein to wrap up the win with a comfortable par.
"I hit some good putts coming down the stretch," said Uihlein, whose father Walter is CEO of golf apparel and equipment manufacturer Acushnet. "When I was at the 17th, I saw Morten was on 15-under and I thought it might have been a little more difficult, but when I got to the 18th green I obviously saw he had dropped back. I'm just delighted to have won."
NOTES: Uihlein was making his 16th European Tour start, His previous best performance on the circuit was a fourth-place finish at the 2013 Tshwane Open ... Tullo recorded two wins on the Challenge Tour in 2010 ... Ten of the past 11 champions at this event have been first-time European Tour winners ... This event ran opposite the World Match Play Championship in Bulgaria.