Roger Federer beats Stanislas Wawrinka in Shanghai to become first player to spend 300 weeks as world No 1 Earlier, Serbian second seed Djokovic looking to wrestle the world number one ranking from Federer barely broke sweat against Spain's Feliciano Lopez, wrapping up a straightforward 6-3, 6-3 victory in front of enthusiastic fans. In-form Djokovic, fresh from his third China Open title in Beijing on Sunday, struck 12 aces and took advantage of some below-par serving by the left-handed Lopez, breaking him three times. "I'm not very well known around the Tour for big serving," said Djokovic, 25. But so far in this tournament, and also in Beijing, 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. US Open champion Murray, 25, proved far too strong for Ukraine's Alexandr Dolgopolov, serving consistently well and seizing on five out of six break points to win 6-2, 6-2 in just 57 minutes. It was the first match of the tournament for the Scot, who had a walkover into the third round. The top eight seeds received a first-round bye. "I think I did a decent job," said Murray. It's very, very different conditions to last week. I think you can see by some of the results here, the guys that have come from Beijing have adapted to the conditions much, much quicker. Fifth seed Jo-Wilfried Tsonga, currently in line to secure the last singles berth in the elite eight-man field at the ATP World Tour Finals, beat Marcos Baghdatis of Cyprus 6-2, 7-6 (7/2) in a contest containing eight breaks. Czech fourth seed Tomas Berdych, sixth in the Race to London, set up a quarter-final meeting with Tsonga after fending off a barrage of 17 aces from American Sam Querrey to win 6-2, 6-7 (3/7), 6-4. Radek Stepanek of the Czech Republic upset eighth seed John Isner of the United States in three sets while 10th seed Marin Cilic of Croatia beat Spain's Fernando Verdasco, also in three sets. As the season enters its final few weeks, Federer, Djokovic, Murray and the injured Rafael Nadal have already qualified for the ATP World Tour Finals. There are four places still up for grabs.