The 25-year-old Horna's only other final appearance came at Long Island in August 2004, where he lost to Lleyton Hewitt.
Horna's victory over Chela, 26, represented his second upset in as many days. He upended No. 2 seed Gaston Gaudio Friday.
With Saturday's win, Horna avenged his loss two weeks ago to Chela in Buenos Aires. That was their first ATP level match. The Peruvian No. 1 has an INDESIT ATP Ranking of 68. Chela is ranked 45. Horna improved his 2006 record to 9-5.
Chela, who won this tournament in 2000, dropped to 3-4 for his career in finals. He last trumped the field at Estoril in 2004. This was his first final since then. Chela's record for the year fell to 10-6.
GO HORNA!!!!!!!!!! YAY! I watched that Tape Delayed last night. And I wanna go to Acapulco. BUT YAY! I LOVE LUIS! I MET HIM! HE'S SO NICE! But I hate his hair-cut, why'd he shave it all off!?! He's barely recognizable now... :-\