Roger Federer rolled into the quarter-finals of the U.S. Open for the 10th time in 11 years on Tuesday, while experience finally got the better of youth at the year's final grand slam.

Five-times champion Federer powered his way past Spain's Roberto Bautista 6-4 6-3 6-2, the 33-year-old raising his record on Arthur Ashe Stadium court to a dazzling 25-1.

Facing Federer for the first time, the 26-year-old Spaniard quickly found himself 5-1 down in the opening set to the 17-time grand slam winner, who then eased off the gas and coasted to an unflustered straight sets win in just under two hours.

On another sweltering day at the U.S. National Tennis Centre, three emerging talents and potential grand slam winners of the future were finally ushered to the Flushing Meadows exit.

Chinese doubles specialist Peng Shuai routed 17-year-old Belinda Bencic 6-2 6-1, Tomas Berdych thrashed 20-year-old Austrian Dominic Thiem 6-1 6-2 6-4, and Frenchman Gael Monfils schooled 23-year Bulgarian Grigor Dimitrov 7-5 7-6(6) 7-5.

Monfils put aside his showman antics for a more workmanlike approach to his fourth round match and it resulted in victory over the player dubbed "Baby Fed" for his all-around game that resembles Swiss maestro Federer's.

Frenchman Monfils, seeded 20th, returns to the quarter-finals for the first time since 2010 for a date with Federer.

"He's got easy top 10 potential," said Federer of Monfils, who has yet to drop a set. "He's a great mover. He's got a wonderful serve, really, which nobody really talks about because of his athletic movement which stands out so much.

"His issues have really been just his fitness and his setbacks he's had because of injury. Then sometimes maybe not wanting to play sometimes because of reasons only he can explain.

"I think I can speak on behalf of so many players: We love watching him play."

'AMAZING TIME'

It was not all joy for the French contingent on Tuesday with Gilles Simon losing to big-serving Croat Marin Cilic.

Cilic and Simon have played a combined 49 five-setters in their careers so it was no surprise that Tuesday's meeting between the two went the distance.

Cilic had won a five-set marathon over Simon earlier this year at the Australian Open and it was the 14th seeded Croatian coming out on top again 5-7 7-6(3) 6-4 3-6 6-3.

While Cilic and Simon battled it out for over four hours in the heat, Federer, Monfils, Berdych, Peng and 10th seed Caroline Wozniacki conserved energy by registering straight-sets wins.

Peng, 28, delivered a 64-minute master class to 2013 junior world number one Bencic in an unlikely quarter-final between unseeded players.

The Chinese had rattled off three impressive upsets in a row from the second round, ousting fourth seed Agnieszka Radwanska, 28th seed Roberta Vinci and 14th-seeded Lucie Safarova, on her way to reaching her first grand slam singles semi-final in 37 attempts.

"This is amazing time for me," said Peng, who has won 16 doubles titles, including this year's French Open, but is still chasing her first singles crown.

"A lot of tennis. It's a long time, the career. It's tough sometimes. I'm thinking to give up and stop play because I don't know if I can make it or not."

Peng will next meet former world number one Wozniacki, who used her aggressive groundstroke game to near perfection in a 6-0 6-1 victory over Italy's Sara Errani.

The 10th-seeded Dane, engaging Errani in long baseline rallies but using superior power to open up the court and find lanes for blasting home winners, roared to victory in a brisk 65 minutes at Arthur Ashe Stadium.

(Editing by Peter Rutherford)