Novak Djokovic put in another powerful serving performance on his way to a comfortable 6-3, 6-3 victory over Feliciano Lopez in the third round of the Shanghai Masters.
Djokovic, who beat Grigor Dmitrov in the second round, was again rarely troubled on his serve, firing 12 aces to set up a meeting with German Tommy Haas in the quarterfinals.
"I'm trying to enjoy the efficiency of my serve," the Serbian said. "I'm not very well known around the tour for big serving. But so far in this tournament, and also in Beijing (at the China Open), it has been working very well for me.
"It has been giving me a lot of free points, a lot of confidence into the matches.
"This is a bit faster surface compared to the one I played last week, maybe compared to the majority of the hard court tournaments we're playing. So serve, advantage of having good serve, precise serves, is really very much needed in these circumstances."
Djokovic said some smart decisions had helped him remain fresh at the end of this year, after tiring out towards the end of last season.
"The scheduling more or less was similar in these two seasons," he said. "I haven't changed my routines that I've been respecting in practices, preparation and recovery programs. It all has been the same.
"But I've made maybe a couple of more wiser decisions on how to play, what to play, what to do in order to stay fit. I've had very long and emotional 2011. Winning the US Open also brought me a lot of joy, but a lot of fatigue also. I went back to Serbia and played a Davis Cup match, which got my injury worse, then I had to be away for two months also.
"This year hasn't been the case. I haven't played a Davis Cup. Maybe that helped me to stay fit. But I'll be having Davis Cup matches in the next year hopefully. I'm really looking forward to play for my country once again. I'll try to keep the good scheduling as a priority."
Djokovic, ever popular wherever he goes, has received a lot of gifts from his fans over the past week or so, and the Serbian said he was extremely impressed with the artistic ability of the Chinese people.
"I have many, many presents already here in Shanghai in these couple days," he said. Many different ones. I got some masks.
"Usually the presents that I get are the ones which are associated in some way with Chinese tradition. So that's something very nice that I can take home and keep as a nice memory.
"But my favorite ones are the albums that they make. It's incredible. I've been saying it, I'll say once again, I'm impressed with the talent they have for drawing things. I think China has a great future in art because they are really, really good at it."
Results: Roger Federer bt Stanislas Wawrinka 4-6, 7-6, 6-0; Novak Djokovic bt Feliciano Lopez 6-3, 6-3; Andy Murray bt Alexandr Dolgopolov 6-2, 6-2; Tomas Berdych bt Sam Querrey 6-2, 6-7, 6-4; Jo-Wilfried Tsonga bt Marcos Baghdatis 6-2, 7-6; Tommy Haas bt Janko Tipsarevic 6-2, 6-1; Radek Stepanek bt John Isner 6-4, 6-7, 6-3; Marin Cilic bt Fernando Verdasco 4-6, 6-1, 6-4.
