( CNN ) -- Andy Murray and Novak Djokovic maintained their title charges in Tokyo and Beijing with quarterfinal victories by contrasting routes Friday . Murray was extended to three sets in beating Switzerland 's Stanislas Wawrinka for this 50th win on the ATP Tour this year and the 10th in a row . Djokovic needed less than an hour to beat Austria 's Juergen Melzer 6-1 6-2 at one of his favorite venues . He won the China Open title in 2009 and 2010 but did not defend his crown last year . The Serbian , beaten by Murray to lose his U.S. Open crown last month , converted all four of his break points and fired 12 aces in a near flawless display . `` The serve was great tonight . It 's one of the best serving matches I have had in my career , so that 's a positive sign . I will try to keep on going , '' he told the official ATP Tour website . Djokovic will play Germany 's Florian Mayer as he bids to reach his ninth final on tour this year . Spain 's Feliciano Lopez will play third seed Jo-Wilfried Tsonga of France in the other semifinal Saturday . In the women 's draw , Li Na beat defending champion Agnieszka Radwanska of Poland 6-4 6-2 to secure reach the semifinals and seal her place in the season-ending WTA Championships in Istanbul . Top seed Victoria Azarenka and Maria Sharapova are also in the last four . World No.3 Murray looked set to wrap up an easy win over Wawrinka , one of his victims as he won Olympic gold in London , when he took the first set with two breaks of service . But Wawrinka hit back to force a decider before the Britain pulled away again with two more breaks to wrap up the match in two hours 50 minutes . He will face Milos Raonic of Canada for a place in the final . The Canadian , beaten by Murray in the fourth round at the U.S. Open , saved a match point before beating Janko Tipsarevic 6-7 6-2 7-6 . `` I 'll try to do what I did in New York . I got a lot of returns in play . Once I was in the point , I was able to dictate a lot of them so I 'll try and do the same tomorrow , '' Murray said as he looked forward to their last four clash . Home hopes were kept alive by eighth seed Kei Nishikori , who became the first Japanese player to reach the semifinals of their home open . He upset second seed Tomas Berdych 7-5 , 6-4 Friday and will now take on Marcos Baghdatis , who beat qualifier Dmitry Tursunov 6-2 6-4 .
Li Na reaches semifinal of Tokyo Open in Tokyo . Title holder needs three sets to beat Stanislas Wawrinka . Agnieszka Radwanska powers into last four at China Open in Japan . Li Na puts out defending champion Novak Djokovic .