BELEK Turkey (Reuters) - Young American Brooks Koepka looked as cool as a cucumber as he won a battle royal with Ian Poulter to claim the first regular tour victory of his career at the $7 million Turkish Airlines Open on Sunday.
The 24-year-old's triumph also meant Rory McIlroy was confirmed as Europe's 2013-14 money-list winner ahead of next week's season-ending DP World Tour Championship in Dubai.
Koepka and the 38-year-old Poulter were locked together at the top of the leaderboard until the youngster struck a majestic approach at the 13th and nonchalantly rolled in a 12-foot eagle putt to burst two strokes clear.
The Englishman, playing in the match behind, had to make do with a birdie at the 13th and the destiny of the title eventually rested on developments at the 18th.
The bearded Koepka could only manage a par five at the last after pushing his tee shot into the tall pine trees that line the Montgomerie Maxx Royal and being forced to chip the ball out sideways.
Poulter found sand with his approach and then the man who is normally so reliable with the putter in Ryder Cup combat missed a glorious opportunity to set up a sudden-death playoff when he failed to hole his birdie attempt from five feet.
"This is awesome," Koepka told Sky Sports television after a closing seven-under 65 gave him a 17-under tally of 271. "I played well and obviously Poulter did too.
"This field is first class. Some of the best players in the world and it's nice to get the win.
"To make that eagle putt was very big for me to build momentum over the last few holes," said Koepka as the sun came down over the still waters of the Mediterranean in the distance.
Poulter (67) finished on 272, two ahead of Swede Henrik Stenson (64) and three in front of Spain's Miguel Angel Jimenez, overnight leader Wade Ormsby of Australia and English pair Andy Sullivan and Danny Willett.
The Turkish Open is starting to develop a habit for first-time winners, after Frenchman Victor Dubuisson triumphed in the inaugural edition 12 months ago, and Koepka's victory underlines his status as one of the hottest young prospects in golf.
The American, who has won four times on the second-tier European Challenge Tour, told Reuters in an interview on Saturday that he would be disappointed if he ended the season without a breakthrough title.
Once he wrested the initiative away from Poulter, he had to show nerves of steel at the 17th.
Koepka was startled by a scream on his backswing, leaving him to shake his head and look daggers at the crowd after missing the green with a wayward approach.
His ball nestled in deep rough but he played a sumptuous recovery to three feet and knocked in his par-saving putt.
Koepka's win earned him a cheque for 930,000 euros ($1.16 million) and will see him climb from 61st in the world into the leading 40, which brings an automatic ticket to the majors and the World Golf Championship events.
Poulter looked back ruefully at the six-shot lead he squandered by slumping to a 75 in the third round.
"The damage was done on Saturday," he said. "It is really disappointing to have played three great rounds and to have one blip.
"It's frustrating, no other word for it, and, yes, I'm going to be angry for a good few days. I'll keep myself in my own little room and have a little chat with myself and come out and win next week."
Spain's Sergio Garcia, Marcel Siem of Germany and Welshman Jamie Donaldson needed to win here to have any chance of denying McIlroy his second money-list title in three years.
"Massive congrats to my good buddy @BKoepka on the win in Turkey! Very well deserved, enjoy the celebrations!" said the Northern Irishman on his Twitter account.
Editing by Toby Davis and Ian Chadband