Paris - David Nalbandian defeated compatriot Juan Del Potro for the second week in a row, earning a 6-4, 6-0 victory in the third round of the Paris Masters on Thursday.

Nalbandian's victory over his 20-year-old rival also mathematically delayed Del Potro's chance of formally clinching a place in the Masters Cup.

Del Potro has been nursing a painful split toenail for months, with no time to have it removed until after the Davis Cup final with Spain in late November.

He remains on provisional seventh in the race to the eight-man season-wrap event in Shanghai starting a week from Sunday.

Paris  - Roger Federer is keeping focus as he heads into the business end of the ATP season, with solid performances laying the groundwork for what he hopes in a return to world-class wins in 2009.

The Swiss claimed his home Swiss Indoors in Basle for the third time at the weekend before making a late confirmation of his entry into the Paris Masters.

He then leaves early next week for Shanghai to defend his title in the season-ending Masters Cup.

Paris  - The back-pain drama which has limited Marcos Baghdatis to just 24 ATP starts this season came back to haunt the Cypriot as he was forced to retire for the third time in four matches on Monday at the Paris Masters.

The 2006 Australian Open finalist has struggled in the 2008 season with ankle and back problems. But after completing a match last week in Basle - even a loss - his spirits were again rising.

That all ended at the Bercy arena as American Sam Querrey earned a victory 7-5, 6-7 (5-7), 3-2 when Baghdatis was again frustratingly forced to retire.