Cincinnati Masters: Andy Murray into last eight, Johanna Konta beaten
Olympic champion Andy Murray beat South Africa's Kevin Anderson 6-3 6-2 to reach the quarter-finals of the Cincinnati Masters.
It was Murray's 600th victory and he is on a career best 20-match winning streak, with Australia's Bernard Tomic his next opponent on Friday.
Briton Johanna Konta lost 6-7 (1-7) 6-4 6-0 to fifth seed Agnieszka Radwanska.
Rafael Nadal suffered a surprise 6-1 6-3 loss to Borna Coric, and the Spaniard admitted he is struggling physically.
He arrived in Cincinnati on Monday, on the same private jet from Rio as Andy Murray, having won the doubles and reached the singles semi-finals at the Olympic Games.
"Too tired," said the 14-time Grand Slam champion, who returned to action in Rio for the first time since pulling out of the French Open in May.
"Elbow, shoulder. Two and a half months without competing and especially without practising, and to do what I did in the Olympics and come here - too much."
Tomic caused an upset against another Olympian, Japan's Kei Nishikori - the man who beat Nadal to bronze in Rio - with the Australian coming through 7-6 (7-1) 7-6 (7-5).
Second seed Stan Wawrinka also went out, as Bulgaria's Grigor Dimitrov saw off the Swiss player 6-4 6-4.
Murray, 29, looks increasingly able to challenge Novak Djokovic - absent from Cincinnati with a wrist injury - for the world number one ranking over the remainder of the year.
"It's cool that it happened in Cincinnati," the Scot said of claiming his 600th Tour win. "I got a wild card here when I was 18. I also won my first Masters 1000 here, so it's a place that means a lot to me."
In the women's draw, Germany's Angelique Kerber reached the last eight with a 7-6 (7-5) 6-4 victory over Barbora Strycova and will next play Carla Suarez Navarro.
Kerber will replace Serena Williams as world number one if she wins the Cincinnati title - the American missed the tournament with a shoulder injury,