Seve Trophy by Golf+ team-mates Scott Jamieson and David Lynn topped a congested leaderboard midway through a thrilling final round of the Portugal Masters at Oceânico Victoria Golf Course.
Overnight leader Paul Waring immediately came back to the field when he bogeyed the first, missing from ten feet for par.
He then parred his way to the turn to remain 15 under, in an event where the winner has been at least three shots off the 54-hole pace four years running.
That allowed Jamieson and Lynn to sneak ahead as they advanced to 16 under par, but with only three shots covering the top 12 players it was still all to play for.
Jamieson, whose only European Tour event came in an event reduced to 36 holes, hit his approach to two feet at the second and turned in a two under 33.
England’s Lynn – who like Jamieson was on the beaten Great Britain & Ireland team in Paris last week – was six under for his round with four holes remaining and looked likely to post a challenging clubhouse target.
Waring, Welshman Jamie Donaldson and Spain’ Pablo Larrazábal were all one behind coming into the home straight.
Lynn collected his eighth birdie of the day from six feet at the 15th to move into the outright lead on 17 under, but Jamieson – who came within a whisker of The European Tour’s first 59 on Saturday – still had plenty of holes remaining.
Lynn, whose only previous European Tour title from almost 400 events came in the KLM Open in 2004, moved two shots ahead with a birdie on the 17th, his third shot to the par five finishing just inches from the hole.
The former US PGA Championship runner-up then parred the last despite his approach flirting with the water to set the clubhouse mark at 18 under.
Austria's Bernd Wiesberger had moved to 17 under with his third birdie in succession on the 16th, with Waring, Jamieson, Larrazábal and South African Justin Walters all on 16 under.
Jamie Donaldson had looked certain to move 17 under after a brilliant approach to the 13th, but somehow three-putted from three feet to drop back to 15 under.
Wiesberger's chances effectively disappeared when he found the water with his second shot on the 17th, but playing partner Walters made a birdie and then holed from 40 feet from across the 18th green for a most unlikely par.
At 17 under Walters, who lost his mother two weeks ago, was alone in second and after starting the week 126th on the Race to Dubai, looked certain to have done enough to climb inside the top 110 and keep his card for next season.