Novak Djokovic stepped up his level of play Thursday after a six-week injury break, cruising to a 6-1, 6-2 victory over Lukasz Kubot in the Swiss Indoors second round. The top-ranked Serb, who rested to treat a back injury, needed just 55 minutes to defeat the 64th-ranked qualifier from Poland. Djokovic improved to 66-3 this year in his first tournament since winning the US Open in September. He will play Marcos Baghdatis of Cyprus in the quarterfinals Friday. Also Thursday, there were second-round wins for unseeded trio Florian Mayer of Germany, Kei Nishikori of Japan and 113th-ranked Mikhail Kukushkin of Kazakhstan. Mayer beat Ivan Ljubicic 6-3, 6-1 for his first victory in four matches against the big-serving Croat. Nishikori continued to make good use of his wild-card entry, beating Andreas Seppi of Italy, 6-3, 7-6 (4). Kukushkin reversed his qualifying-round loss against James Blake to beat the American 6-3, 6-4. He got into the main draw after Sunday's defeat as a lucky loser and will play Nishikori in the quarters. Querrey upsets Tsonga Sam Querrey beat Jo-Wilfried Tsonga 7-6 (5), 6-2 to reach the Valencia Open quarterfinals Thursday, dealing a blow to the second-seeded Frenchman's hopes of qualifying for the ATP World Tour Finals. The American player secured his first back-to-back ATP match wins since June to leave Tsonga relying on his performance at next week's Paris Masters to clinch one of the final three places for the season-ending event in London. Juan Monaco won his second-round match 6-3, 6-1 over Fabio Fognini, while 2010 finalist Marcel Granollers also reached the last eight. Ivanovic prevails Ana Ivanovic suffered an injury scare as she began the defense of her title at the Tournament of Champions with a 6-3, 6-3 win over Italy's Roberta Vinci. Ivanovic, who will celebrate her 24th birthday in Bali on Sunday, will play Nadia Petrova in the semi-finals after the Russian upset Chinese second Peng Shuai 6-4, 6-3.
