Djokovic, del Potro, Federer reach Paris Masters QFs

Paris, France ( - Second-seeded Novak Djokovic, hot Argentine star Juan Martin del Potro and former world No. 1 great Roger Federer were among Thursday's second-round winners at the $3.65 million Paris Masters tennis event.

The former top-ranked stalwart Djokovic came from behind to beat big-serving 13th-seeded American John Isner 6-7 (5-7), 6-1, 6-2 on the hardcourts at Palais Omnisports de Paris-Bercy. Djokovic broke Isner on four occasions, while the towering American was unable to break the reigning Australian Open champion on Day 4 in the French capital.

The recent China Open and Shanghai Masters champion Djokovic extended his current winning streak to 14 matches.

"In China, I have had probably the best two weeks of the year, except at the beginning of the year, so it gives me a lot of confidence," Djokovic said. "I feel that I'm back mentally where I need to be, and hopefully I can maintain this winning streak."

Djokovic, who titled here in 2009, will battle Swiss slugger Stan Wawrinka in Friday's quarterfinals.

The fourth-seeded del Potro is trying to reach his fourth final in four events, and he inched closer to that on Thursday by overcoming recent Stockholm champion Grigor Dimitrov 3-6, 6-3, 6-4.

Del Potro beat Federer in last week's marquee Swiss Indoors Basel finale and the two stars will meet again in a quarterfinal showdown in Paris on Friday.

A fifth-seeded Federer, meanwhile, foiled Philipp Kohlschreiber 6-3, 6-4 to improve to 8-0 lifetime against the quality German. Federer was the Paris Masters titlist two years ago.

In other action involving top-10 stars, third-seeded and defending Paris Masters champion David Ferrer leveled 15th-seeded Frenchman Gilles Simon 6-2, 6-3; sixth-seeded 2005 winner Tomas Berdych got past 10th-seeded rising Canadian Milos Raonic 7-6 (15-13), 6-4; a seventh-seeded Wawrinka waltzed past 12th-seeded Spaniard Nicolas Almagro 6-3, 6-2; and ninth-seeded Frenchman Richard Gasquet rolled past Japanese Kei Nishikori 6-3, 6-2. Ferrer and Berdych will do battle on Friday.

Ferrer, who was a runner-up in Valencia in his native Spain last week, bested 6-foot-8 Pole Jerzy Janowicz in last year's Paris Masters final.

Wawrinka and Gasquet secured the final two spots for next week's prestigious season-ending eight-player ATP World Tour Finals in London.

This week's big winner will collect $720,000.