New York: Three-time champion Serena Williams stormed to a double bagel 6-0, 6-0 rout of Czech Andrea Hlavackova to reach her 10th US Open quarter-final on Monday in a ruthless display of her title credentials.
The 30-year-old American allowed the world number 82 just eight points on her serve and finished the last-16 clash with 31 winners against just seven unforced errors, backing up her 57-minute win with eight aces.
Williams, a 14-time Grand Slam title winner, and the reigning Wimbledon and Olympic champion, has dropped just 12 games in four matches at the Open this year.
She hasn't lost a game in her last three sets played while Monday's mauling was the fifth time in her career she had handed out a double bagel.
Williams will on Wednesday face Ana Ivanovic for a place in the semi-finals after the Serb 12th seed defeated Bulgaria's Tsvetana Pironkova 6-0, 6-4.
The other quarter-final will feature Italian compatriots, best friends and doubles partners Sara Errani and Roberta Vinci battling for a semi-final spot.
Errani, the 10th seed, defeated last year's semi-finalist, German sixth seed Angelique Kerber 7-6 (7/5), 6-3, while Vinci saw off Polish second seed Agnieszka Radwanska 6-1, 6-4.
It will be the first time two Italian women have made the last eight at the same Grand Slam.
Tuesday's first quarter-finals see top seed Victoria Azarenka facing defending champion Samantha Stosur while 2006 winner Maria Sharapova takes on France's Marion Bartoli.
"Andrea played really well," Williams insisted of her outclassed opponent, who departed the singles tournament $120,000 richer for making the fourth round of a Grand Slam for the first time.
"She never gave up. She's such a great fighter. But I played really well today, I tried to stay relaxed and do what I do."
Williams dismissed suggestions that the 2012 title was already a formality.
"I think my road has been a journey. I don't think anything's easy. I don't think anything is easy," she said.
"I never play a person and say, 'Oh, that was an easy opponent.' No, I have never done that. Everything takes some type of match and mental toughness."
Williams has now reached a 34th quarter-final at a major.
Ivanovic booked her first Grand Slam spot in four years -- and first ever at the US Open -- by defeating Bulgaria's Tsvetana Pironkova 6-0, 6-4.
Ivanovic has never taken a set off Williams in her three defeats; two of those losses came at the US Open in 2006 and 2011.
The 24-year-old Ivanovic's last major quarter-final came on the way to her one and only Grand Slam triumph at the 2008 French Open.
"I hardly made any mistakes in the first set but she is a tough opponent and I knew she would come back in the second set," said Ivanovic, after her 71-minute win, where she finished with 28 winners and 21 unforced errors.
"It's amazing to be in my first quarter-final at the US Open."
Errani, 25, the French Open runner-up, made her first US Open quarter-final in what has become her best year on the tour which has brought her four singles titles and seven doubles trophies.
"It was a difficult fight today," said Errani. "The first set was one hour and 15 minutes. It was very tactical."
Vinci had lost all four previous meetings with Wimbledon finalist Radwanska, who has yet to get beyond the fourth round in New York.
The 29-year-old will be playing in a Grand Slam quarter-final for the first time.
"I just closed my eyes and played. The ball was big enough," said Vinci.
"I am happy to play Sara. She is my best friend and I am happy she won today."