Men’s singles Fourth round results Cilic bt Kližan 7-5, 6-4, 6-0Berdych bt Almagro 7-6, 6-4, 6-1Women singlesErrani bt Kerber 7-6, 6-3NEW YORK – Andy Murray produced a masterclass in tennis to destroy the highly rated Milos Raonic on Monday and book his place in the quarter-finals of the U.S. Open.The Olympic champion provided more evidence he could be ready to add a first grand slam title to the gold medal he won in London last month when he blunted one of the biggest serves in the game to win 6-4 6-4 6-2.Serena Williams was just as ruthless as she charged into the women’s quarters with a 6-0 6-0 win over Czech Andrea Hlavackova while Roger Federer was gifted a spot in the last eight when Mardy Fish withdrew from the year’s final grand slam.Showing no mercy against her 82nd ranked opponent, Williams sent an ominous warning of her intention to add the U.S. Open title to her recent wins at Wimbledon and the London Olympics with a rare ‘double bagel’ victory in 57 minutes.The American’s next opponent is Serbia’s Ana Ivanovic, a former world number one who has rediscovered her best after a lean few years where she struggled with injuries.Ivanovic advanced on Monday with an impressive 6-0 6-4 victory over Bulgarian Tsvetana Pironkova but said she would have to raise her game even higher to compete with Williams.Federer advanced to his 34th consecutive grand slam quarter-final without hitting a ball on the Labor Day holiday in the United States as Fish pulled out with an undisclosed health issue."I am really sorry for Mardy,” Federer said. "I just want to wish him a speedy recovery. We all want to see him back on tour soon.”World number one Federer has not dropped a set in this year’s U.S. Open at Flushing Meadows. The 31-year-old Swiss will now play Tomas Berdych after the Czech sixth seed thrashed Spain’s Nicolas Almagro 7-6 6-4 6-1.Poland’s Agnieszka Radwanska, the women’s second seed, became the highest ranked casualty of the tournament when she lost to Roberta Vinci 6-1 6-4.The Italian will now play doubles partner and best friend Sara Errani after she upset Germany’s Angelique Kerber 7-6 6-3.