Federico Delbonis claimed his maiden ATP title at the Brazil Open, battling back from a set down to defeat Paolo Lorenzi 4-6 6-3 6-4.
Argentine Delbonis broke Lorenzi's serve right at the start start the decisive set and held on to close out the match after two hours and six minutes on court.
"To tell you the truth, I have no words," the champion said afterwards. "I played well match after match. It was a great result in the end."
The 23-year-old broke his duck having played in only one final previously, going down to Italian Fabio Fognini of Italy in Hamburg last July after upsetting Roger Federer in the previous round.
Italian Lorenzi - who had beaten his left-handed opponent three times before in challenger events - had never previously been past the quarter-finals of a singles tournament.
It's a shame I wasn't able to win," the losing finalist said. "But hopefully I'll be back next year to try again."
For the first time since 2007 a Spanish player has not lifted the trophy. Rafael Nadal won in 2013 but opted not to defend this year.