Irishman Shane Lowry beat England's Ross Fisher by one at the Portugal Masters after a thrilling final day in Vilamoura.
The 25 year old, who captured the Irish Open in an amazing debut three years ago, became only the second player to win on The European Tour as both an amateur and a professional.
Lowry joins Spaniard Pablo Martin, who won the 2007 Portuguese Open in his amateur days and then the Alfred Dunhill Championship in South Africa two years later.
Shot of the day from Lowry was a seven iron into the hole for an eagle two at the 11th, who looked to have secured a play-off until Fisher three-putted the last for bogey.
Lowry was one ahead after adding birdies at the 15th and 17th, but prepared himself for a play-off after driving into sand and bogeying the last for a 66 and 14 under par total.
Former Ryder Cup star Fisher was in the group behind and from the fringe of the green left his long birdie attempt - a putt to win the title - five feet short and then lipped out.
Unlike his maiden victory, which earned him nothing because of his amateur status, Lowry this time picked up a cheque for €375,000 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.
"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 Oceânico Victoria Golf Course.
"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 tenth 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 remain on terms when Lowry handed him a reprieve with a bogey at the last.
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 a serious loss of form since beating Tiger Woods at Pinehurst. He fell outside the Official World Golf Ranking'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.