Big three through in Shanghai
Defending champion Andy Murray was joined by Roger Federer and Novak Djokovic in the last eight of the Shanghai Masters.
The recent US Open winner will now face the Czech Republic's Radek Stepanek in the next round after seeing off Alexandr Dolgopolov of Ukraine 6-2 6-2 in under an hour.
But seven-time Wimbledon champion Federer had a rougher Thursday afternoon thanks to a resilient Stanislas Wawrinka with Djokovic edging out Feliciano Lopez earlier in the day.
Wawrinka took the first set with relative ease, winning 70% of his points on his serve, before rallying to set up a tense tie-break at the end of the second set.
But Federer capitalised on his opponent's sudden inability to return the ball to earn a final set, during which he won three break points to seal a 4-6 7-6 (7/4) 6-0 victory and a quarter-final showdown with Marin Cilic.
The Croatian also had to recover from a set down to dismiss Spain's Fernando Verdasco 4-6 6-1 6-4.
Federer told Sky Sports 1: "He didn't give me too many opportunities and I knew it would be extremely difficult.
"I'm relieved to get through and be moving on to give myself another opportunity.
"And if the opportunity presents itself, I'd love to finish the year as world number one."
But Djokovic also remains on course to return to the top spot having seen off Lopez 6-3 6-3.
The Serb broke his opponent three times to set up a quarter-final meeting with Tommy Haas, who beat Janko Tipsarevic 6-2 6-1.
A proliferation of aces from Djokovic's compatriot were not enough to save him from a third-round exit at the hands of the German veteran.
France's Jo-Wilfried Tsonga booked his progression to the next round after coming out on top in an exciting battle against former Australian Open finalist Marcos Baghdatis.
There were eight breaks of serve as Tsonga struck 11 aces to oust the Cypriot 6-2 7-6 (7/2).
The Frenchman will now face Tomas Berdych of the Czech Republic, who fended off a barrage of 17 aces from Sam Querrey to win 6-2 6-7 (3/7) 6-4.