Andy Roddick and Juan Martin del Potro boosted their chances of qualifying for next month's Masters Cup by winning their second-round matches in straight sets at the Paris Masters on Tuesday. Third-seeded Novak Djokovic was leading 6-2, 4-3 against Dmitry Tursunov when the Russian retired with an injured right shoulder, seventh-seeded Roddick beat Feliciano Lopez of Spain 6-3, 6-4, ninth-seeded del Potro beat Mario Ancic of Croatia 6-0, 6-4, and 16th-seeded Gael Monfils topped Juan Monaco of Argentina 6-4, 6-4 to set up a possible match against top-ranked Rafael Nadal. Tursunov retired against Djokovic after twice needing treatment on his shoulder. Djokovic, the Australian Open champion, hasn't won a title since his third of the year at the Rome Masters in May. “Still trying to find my top form. Lately I've been struggling on the court,” Djokovic said. “But still, I'm fighting. I know that I have to fight for every point and just find my best shape.” Djokovic has never gone beyond the third round at the Paris Masters and next plays either No. 13 Jo-Wilfried Tsonga or 2004 runner-up Radek Stepanek in the third round. Roddick and del Potro are chasing the last three spots for the season-ending, eight-man Masters in Shanghai. Roddick was sixth in the standings and del Potro seventh heading into this week's indoor tournament at Bercy Indoor Arena. Gilles Simon, in the eighth spot, will play Igor Andreev in the second round on Wednesday. If he wins, Simon will face Roddick in the third round. Monfils, meanwhile, was celebrating his first appearance in the Paris Masters third round. “I wanted to do so well. Juan is a very good player, and he beat me twice already,” Monfils said. “Thanks to my serve I was able to be more confident.” In first-round action, new Lyon Grand Prix champion Robin Soderling won his sixth straight match against Josselin Ouanna of France 6-3, 6-4 to set up an eighth career meeting with Roger Federer. Soderling is 0-7 against Federer, who won his 57th career title at the Swiss Indoors on Sunday. Germany's Philipp Kohlschreiber beat Russia's Mikhail Youzhny 6-1, 6-4; 2005 runnerup Ivan Ljubicic of Croatia beat Viktor Troicki of Serbia 6-3, 6-4; and Stepanek of the Czech Republic downed Marc Gicquel of France 6-4, 3-6, 6-4, and Florent Serra beat Guillermo Canas of Argentina 4-6, 7-5, 6-3. Serra will meet Nadal next. Ljubicic will play 2006 champion Nikolay Davydenko of Russia. Kohlschreiber had to save eight break points, and next plays fifth-seeded David Ferrer of Spain. Ferrer is just behind Simon in the race for Masters berths, with James Blake, Stanislas Wawrinka and the Australian Open finalist Tsonga all hoping a good showing will help them qualify. – AP __
