The second seed from Santiago, battling against blustery conditions, clinched victory in the clay-court event by outplaying the unseeded Spaniard, Felix Mantilla, 6-2, 6-4.
Rios, a 20-year-old hailed as the Andre Agassi of South America, shrugged off a slow start and the loss of his first service game to take the next six games and consequently the first set.
"I felt very good apart from at the start," Rios said. "But overall I think I played great at this tournament. It was the right decision to play here before Paris."
Jana Novotna will also go into Paris with her confidence high after defeating Magdalena Maleeva in the final of the Spanish Open in Madrid yesterday.
Novotna beat her Bulgarian opponent 4-6, 6-4, 6-3 in the tournament, which is also played on clay. The Czech's path to the title had been made easier when Monica Seles dropped out with of a shoulder injury.
Marc Rosset, the Olympic champion, steered Switzerland to their first World Team Cup title with a 2-1 victory over the Czech Republic in Dusseldorf yesterday.
Petra Korda, the former French Open runner-up gave the Czechs a 1-0 lead with a 6-3, 6-4 defeat of Jakob Hlasek in the opening singles, but Rosset defeated Bohdan Ulihrach 7-6, 6-2 to draw level. Rosset then teamed up with Hlasek to defeat Korda and Daniel Vacek 6-3, 6-4 in the decisive doubles.Reuse content