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.

But should on-fire Frenchman Gilles Simon beat Andy Roddick later that would would drop Del Potro to eighth in the chase.

Nalbandian is defending the Paris title after making a run to the trophy in 2007 with wins over Roger Federer and Rafael Nadal.

Del Potro and Nalbandian have played once per week for the last three at indoor events, with Del Potro winning in Madrid but losing in Basle and Paris.

Nalbandian also remains in the running for a Shanghai spot, but has said repeatedly that he would forego the trip in order to prepare for the Davis Cup final in Mar del Plate from November 21.

Nalbandian spent little more than an hour in his easy win, with Del Potro coming into the match hurting and tired after winning four straight titles over the summer. (dpa)