Top seed Rafa Nadal marched into the last 16 of the Shanghai Masters with a thoroughly entertaining 6-2, 6-7, 6-4 victory over American James Blake Wednesday. US Open champion Juan Martin Del Potro, however, joined the growing casualty list at the $3.24-million tournament, retiring because of a wrist injury while 7-5, 2-1 down to Austrian Jurgen Melzer. In-form second seed Novak Djokovic picked up where he left off in the final of the China Open on Sunday, notching up his 15th win in his last 17 matches with a straightforward 6-3, 6-1 victory over Italian qualifier Fabio Fognini. Fifth seed Jo-Wilfried Tsonga of France took exactly an hour to dismiss Chinese wild card Zeng Shaoxuan 6-3, 6-3 and set up a third-round clash with Swedish ninth seed Robin Soderling. Croatian Ivan Ljubicic proved it was possible to play at the top level after 30, despite the gruelling schedule, by upsetting Spanish seventh seed Fernando Verdasco 6-4, 7-6. Marat Safin bid farewell to his adoring Chinese fans after defeat but not before taking a swipe at his opponent Tomas Berdych and American Andy Roddick. The big Russian, who is retiring after next month's Paris Masters, suggested Berdych had feigned injury during his 3-6, 6-4, 6-4 win and said the Czech needed to “grow up”. Eighth seed Gilles Simon and Gael Monfils, the 11th seed, ensured France would have three players in the third round when they beat Viktor Troicki and Lleyton Hewitt respectively. Sania in quarters India's Sania Mirza became the first player to reach the quarterfinals of the Japan Open Wednesday, beating Viktoriya Kutuzova of Ukraine in straight sets. The 22-year-old Sania, who won the Australian Open mixed doubles with Mahesh Bhupathi this season, took advantage of a rash of double faults from Kutuzova on her way to a 6-4, 6-3 win. In the last eight on Friday, Mirza will play the 2006 champion, Marion Bartoli of France, seeded second. Bartoli, battling for the final spot in the season-ending championships, thumped Japanese wild card Kurumi Nara 6-1, 6-1 in just 61 minutes. In other second-round action, fourth seed Francesca Schiavone of Italy had an unconvincing 6-3, 0-6, 6-3 win over Chan Yung-jan of Taiwan. Seventh seed Melinda Czink of Hungary hit seven aces and seven double faults in beating Vania King of the United States 6-4, 6-2. Suarez Navarro in quarters Fourth-seeded Carla Suarez Navarro of Spain and Petra Kvitova of Czech Republic reached the quarterfinals of the Generali Ladies Wednesday. The 34th-ranked Suarez Navarro defeated Olga Govortsova of Belarus 6-3, 6-4 for her sixth quarterfinal of the season. Suarez Navarro next plays Kvitova, who upset No. 5 Iveta Benesova of Czech Republic 6-4, 7-5. Sara Errani of Italy eased past Tatjana malek of Germany 6-3, 6-0 to enter quarterfinals. In first-round play, second-seeded Agnieszka Radwanska of Poland defeated Monica Niculescu of Romania 6-4, 6-2. Radwanska next plays Alize Cornet of France, who rallied to beat Kristina Barrois of Germany 4-6, 6-3, 6-3. No. 3 Yanina Wickmayer of Belgium defeated Timea Bacsinszky of Switzerland 7-6 (6), 6-4. Top-seeded Flavia Pennetta of Italy routed Meghann Shaughnessy of the US 6-1, 6-1 Tuesday. She next plays Anna-Lena Groenefeld of Germany, who defeated Roberta Vinci of Italy 7-5, 6-1. Julia Goerges of Germany beat sixth-seeded Sorana Cirstea of Romania 6-3, 6