Argentina's David Nalbandian [ Images ] 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 [ Images ] 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 [ Images ] Ivan Ljubicic.

The lucrative year-end tournament has been hit by several big-name pullouts, with Andre Agassi [ Images ] and Rafael Nadal [ Images ] the latest to withdrew with injury on Monday.

Andy Roddick [ Images ], Marat Safin [ Images ] and Lleyton Hewitt [ Images ] all pulled out prior to the start.