Irishman Shane Lowry beat England's Ross Fisher by one at the Portugal Masters on Sunday after both bogeyed the final hole.
Lowry, whose one previous victory came as an amateur in his home Irish Open three years ago, shot a closing 66 that included holing a seven-iron for an eagle two at the 11th.
He was one ahead with one to play, but took five on the last after driving into sand.
As he watched Fisher, seeking his first title since his Ryder Cup debut two years ago, was on the fringe in two - but left his first putt five feet short and lipped out.
Two behind in third place was New Zealander Michael Campbell - his best finish for four years - and fourth was Austrian Bernd Wiesberger, who after leading by one overnight found water on the 11th and 17th.
Unlike his maiden victory, which earned him nothing because of his amateur status, Lowry this time picked up a cheque for just over £300,000 in addition to the trophy.
"I cannot believe this,'' he said after coming from four behind Austrian Bernd Wiesberger in the final round.
"I can't explain how I feel really. It's a dream come true - I'm over the
moon."
Lowry added: "Everyone was referring to me as the fella who won the Irish Open as an amateur, but now I've won such a prestigious event I don't know what to say."
Nothing might match the atmosphere in torrential rain on the day he triumphed at County Louth, but he still had plenty of vocal support at Oceanico Victoria.
"It was like playing in Ireland," he said. "It was crazy. It was great."
Lowry was still three behind at the turn, but birdied the 10th and then saw his approach to the next land a foot short of the flag and hop in.
"I thought then this could be my day and thankfully it is," he said.
"We had a long wait on the 12th tee which was good, I had time to compose myself."
He went ahead for the first time when Wiesberger drove into the lake and dropped a shot on the 11th, but Fisher then produced three birdies in a row to take over at the top.
The 31-year-old was chasing his first success for more than two years, but bogeyed the short 16th to fall behind again and could not get back on terms.
Wiesberger found more water on the long 17th and by bogeying the last as well allowed New Zealander Michael Campbell to take third place on his own.
The 2005 US Open champion has suffered an horrendous slump since beating Tiger Woods at Pinehurst. He fell outside the world's top 1,300 at one point and only two seasons ago made just one cut in 19 starts.
This was his best finish for four years and the last time he had four rounds in the 60s was nine years ago.
Fisher finished runner-up just as he did behind Lee Westwood in Sweden in June.
