BEIJING: Top seeds Novak Djokovic and Caroline Wozniacki powered into the China Open semifinals Friday, while Chinese favorite Li Na earned her best result in her home tournament. Second-seeded Andy Murray, meanwhile, lost to Ivan Ljubicic of Croatia 6-3, 6-2. Defending champion Djokovic, ranked No. 2, fended off all seven break points he faced while breaking Gilles Simon three times on his way to winning 6-3, 6-2. It's the fifth straight time he's beaten the Frenchman. “I'm very happy that my serve is getting better and better, and hopefully I'm going to use it more and more,” Djokovic said. The US Open runnerup is enjoying a surge in form, crediting his semifinals appearance at Wimbledon with providing a boost in confidence. Looking for his second title of the year, Djokovic will meet American qualifier John Isner, who upset fourth-seeded Nikolay Davydenko 7-6 (4), 6-4, serving 18 aces to the Russian's one. Murray, playing his first tournament since the US Open, never threatened Ljubicic, failing to produce a single break point while being broken three times. Ljubicic fired 12 aces, including four in a row to win the sixth game of the second set. Ljubicic will line up against eighth-seeded David Ferrer in the other semifinal after the Spaniard surprised third-seeded Robin Soderling of Sweden 6-2, 6-4. Wozniacki, to be crowned No. 1 for the first time Monday, overcame a painful knee injury in the second set to beat former No. 1 Ana Ivanovic 7-6 (1), 6-3. With her knee heavily taped, Wozniacki returned to the court at 3-1 in the second set and endured a late charge by Ivanovic to beat the Serb for the first time. Although painful, the injury didn't appear serious, Wozniacki said after the match. Ivanovic double-faulted nine times and broke the Dane twice, but Wozniacki applied more pressure and nailed three of 11 break opportunities. Despite her new status, it was just another day on the court, Wozniacki said. Wozniacki next faces Israeli Shahar Peer, who ground out a 7-6 (4), 6-4 win against Switzerland's Timea Bacsinszky. Li gave the Chinese crowd something to celebrate with a hard-fought 7-6 (8), 6-3 victory against Latvian qualifier Anastasija Sevastova to reach the tournament's semifinals for the first time. Next up for Li is second-seeded Vera Zvonareva, who made easy work of French Open champion Francesca Schiavone 6-0, 6-2. Nadal advances In Tokyo, top-ranked Rafael Nadal rushed through his Japan Open quarterfinal to watch some football while second-seeded Andy Roddick was ousted by Gael Monfils in a three-hour nail-biter Friday. Nadal overwhelmed Russia's Dmitry Tursunov 6-4, 6-1 to reserve a semifinals spot. Tursunov, a six-time winner on tour, reached his first quarterfinals on tour this week since he returned to the tour in May following two ankle surgeries. Nadal said he was hoping to finish up early so he could have a quiet dinner and then watch the football friendly between Japan and Argentina. But he said he was not ready yet to start thinking about winning his first title in Japan. “It was a very nice atmosphere,” he said. “But I still have hard matches ahead.” Viktor Troicki spared Nadal from meeting Guillermo Garcia-Lopez - who beat Nadal en route to the Bangkok title last week - by defeating the Spaniard 6-2, 3-6, 6-4. Troicki, who served 14 aces, has yet to beat Nadal. Monfils outlasted Roddick 7-6 (5), 4-6, 7-6 (6) in a nearly three-hour-long match that was won on big serves and well-placed returns. Roddick converted his only break chance in three to win the second set, and it was the only break of the match. Monfils missed all 10 of his break chances, needing to edge 10th-ranked Roddick in tiebreakers. Monfils, ranked 15th and seeded 5th, said he tried to play an aggressive game and push the power-serving Roddick by going to the net and concentrating on placing his return shots. “He has a good first serve, so I focused on my returns,” Monfils said. “I came to the net more often than usual. I knew I could beat him.” Monfils improved his record to 5-3 against Roddick, though the American went into the match with a 3-1 advantage on hard surfaces. Monfils' semifinal opponent will be Radek Stepanek of the Czech Republic, who progressed when Jarkko Nieminen of Finland forfeited because of a fever.