Argentina's David Nalbandian overpowered compatriot Guillermo Coria 7-5, 6-4 to earn his first victory at the season-ending Masters Cup on Tuesday.
Nalbandian's superior athleticism proved decisive in a see-saw first set and the world number 10 dictated the pace in the second, closing out the Red Group match with a thumping forehand down the line.
The result meant world number one Roger Federer became the first player to reach the semi-finals of the $4.45 million event in Shanghai.
Nalbandian lost his opening match to Federer at the weekend while Coria was beaten by Croatia's Ivan Ljubicic.
The lucrative year-end tournament has been hit by several big-name pullouts, with Andre Agassi and Rafael Nadal the latest to withdrew with injury on Monday.
Andy Roddick, Marat Safin and Lleyton Hewitt all pulled out prior to the start.
