SHANGHAI: Rafael Nadal and Roger Federer breezed into the quarter-finals of the Shanghai Masters here on Thursday and Juan Martin del Potro defeated racquet-smashing Alexander Zverev.

World number one Nadal blew away Fabio Fognini in 63 minutes and plays sixth seed Grigor Dimitrov as he pursues one of the few tournaments to have eluded him.

Timeless rival Federer was even faster, dismissing Ukrainian qualifier Alexandr Dolgopolov 6-4, 6-2 in 61 minutes.

The 31-year-old Spaniard Nadal, fresh off the back of triumphs at the US Open and China Open, anticipates a tough encounter against the Bulgarian Dimitrov.

`I played a very good match, I don`t know how many mistakes I made, but very few, said the 16-time Grand Slam winner and top seed in Shanghai. `I have a tough match against Grigor and know I will have to play my best... but I am playing well.

Nadal, enjoying a late-career flourish, defeated good friend Dimitrov on his way to winning the China Open on Sunday, his sixth title of the season.

And he underlined his status as the man to beat in Shanghai as he battered the Italian Fog nini 6-3, 6-1.

Dimitrov, chasing a spot at the season-ending ATP Finals in London, beat American Sam Querrey 6-3, 7-6 (7-3) to set up a Chinese reunion with Nadal.

Federer, the Swiss world number two, plays either of the Frenchmen Gilles Simon orRichard Gasquet in the last eight on Friday.

A mouthwatering Nadal-Federer final on Sunday awaits if the celebrated pair continue at the current rate.

Gutsy Del Potro recovered from a set down to win 3-6, 7-6 (7-5), 6-4 against rising star Zverev and will next play Viktor Troicki or John Isner.

Zverev, 20, was going af ter his sixth title of a breakthrough season and was comfortable in the first set against Argentine Del Potro, the 2009 US Open champion and 16th seed.

The German prodigy and the 29-year-old, whose career has been beset by injury, went toe to toe in the second set and the tiebreak was just as tight until Del Potro grabbed the crucial mini-break.

And then came the turning point -and a flash of anger from third seed Zverev -as he yielded the crucial service break to go 3-2 down in the third set.

Zverev smashed the racquet on the court, then trodden on it, and brutalised it further as he stomped back to his chair.

A f an at least came away with a demolished racquet for a souvenir after the young German handed it to a spectator.

`I don`t understand how I can lose a match where I get broken one time in three sets and not managed to get any chances on his serve, said Zverev, who is tipped to one day make world number one.

Also through are fourth seed Marin Cilic and Spain`s Albert Ramos-Vinolas, they go head to head in the last eight.-AFP