Novak Djokovic fired an ominous warning to his rivals Thursday, easing into the Shanghai Masters quarter-finals as Tomas Berdych and Jo-Wilfried Tsonga stayed on track for the World Tour Finals.
The Serbian second seed, looking to wrestle the world number one ranking from rival Roger 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.
A powerful backhand down the line sealed the match for the 25-year-old and set up a clash against either sixth seed Janko Tipsarevic of Serbia or German veteran Tommy Haas, who play later.
Earlier, fifth seed Tsonga struck 11 aces in seeing off the challenge of former Australian Open finalist Marcos Baghdatis of Cyprus 6-2, 7-6 (7/2) in a contest containing a surprising eight breaks of serve.
The Frenchman, 27, said he was happy with his game and was focusing on the task in hand rather than on London. He is currently in line to secure the last singles berth in the elite eight-man field.
"For the moment I think about this tournament," he said. "You know, I try to play my best tennis. After, of course for me London is a goal. But I also have another goal, to win some tournaments and try to beat the guy before me."
Czech fourth seed 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.
Berdych cantered through the first set, breaking the 6 feet 6 inches (198 cm) Querrey twice. The 22nd-ranked American levelled the match in a second set tie-break but an early break for the Czech in the third set proved decisive.
Federer and defending champion Andy Murray are also in third-round action on Thursday, where a win for the Swiss 17-time Grand Slam champion will guarantee a 300th week in his career as the top-ranked player.
"I'm obviously excited," said Federer, who meets compatriot and 13th seed Stanislas Wawrinka. "It's a big number, even though 299 or 300 doesn't make a big difference for me. It's obviously a big match for me.
"Obviously it's not a final, so I'm not going to go in super-nervous about it. It's just more the difficulty of playing a good friend. That adds to the special occasion."
Even if Federer loses he will remain at number one after this week if Djokovic does not win the title in China.
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.