Argentina's Carlos Berlocq rallied to overhaul Czech top seed Tomas Berdych 0-6, 7-5, 6-1 on Sunday to win his second career title with victory at the Portugal Open.
The world number 62 becomes the sixth tournament winner over the age of 30 this year on the ATP with his victory in two hours, nine minutes against the world number six.
Berdych was the South American's second top 10 victim of the week after putting out ninth-ranked Milos Raonic of Canada in the quarter-finals.
"This is truly a dream for me," said the winner, who found his form just in time after losing the opening set in 28 minutes.
But the South American baseliner, whose on-court grunting has irritated a string of rivals in recent years, regained his poise and slowly began to make inroads against the top seed playing on a wild card.
"To win this title today, I had to beat one of the best in the world. It was an honour to play and to win this final," he said.
"It was really tough for me at the start, he was playing very aggressive. But I managed to slowly lift my game and get into the match.
"For me, the second set was like starting everything all over again. I managed to improve throughout the second and third sets and somehow I got the win."
Berlocq became the fifth Argentine to win at the venue after Juan Martin del Potro (2011, 2012), David Nalbandian (2002, 2006) Gaston Gaudio (2005) and Juan Chela (2004).
Berdych came to the court with a 3-0 record in his series against the Argentine and had beaten Berlocq on clay in Dusseldorf and in Davis Cup.
The Czech was bidding for the ninth title of his career while Berlocq added to his other trophy from Bastad in Sweden last summer.
Berdych was momentarily derailed by a second-set time violation called by umpire Fergus Murphy.
After regaining his composure after several games of complaining about the call, Berdych found himself in trouble -- he was broken in the final game of the second set and never recovered.
In the third set, Berdych dropped to 0-5 before getting a break-back.
A double-fault a game later set up a match point, which Berdych saved before going down to the loss when his sliding volley hit the net on a second Berlocq match point.
"This was a tough loss but Carlos played really well, he opened it up after the first set. He showed he's a big fighter and that he can do well on his court, on clay," said Berdych.
"It was still a good week for me, I'm glad I could come and play as a wildcard.
"Everything went well up until the final. It's always disappointing to lose a match, but it's like that one day and different the next."
Berdych suffered only his sixth loss of the season while Berlocq improved his season record to 9-7.