Andy Murray blasts past Grigor Dimitrov

Second seed and 2012 champion Andy Murray crushed Bulgaria’s Grigor Dimitrov 6-1, 6-2, 6-2 to reach a sixth US Open quarter-final Monday, clocking up a personal fast serve record in the process.

The 29-year-old reigning Wimbledon and Olympic champion stormed to an impressive seventh win in 10 meetings against the 22nd-seeded Dimitrov.

From the moment Murray broke for a 3-1 lead in the first set, on the back of a lung-busting 32-shot rally, the outcome of the Arthur Ashe Stadium clash was never in doubt.

For good measure, Murray sent down his fastest ever serve of 141mph (226.9 km/h) at the end of a set where he allowed Dimitrov just five points on his service. “I once hit a 145mph serve in San Jose but they recalibrated the machine the next day so it didn’t count. Tonight was the first time I have gone above 140,” said the 29-year-old.

“It was lucky and I doubt I’ll ever do it again.” Dimitrov committed 43 unforced errors as Murray set up a last-eight clash with Japanese sixth seed Kei Nishikori, the 2014 runner-up who downed 37-year-old Ivo Karlovic 6-3, 6-4, 7-6 (7/4).

Karlovic fired 21 aces in the contest but Nishikori’s 44 winners and a miserly seven unforced errors proved the key.

Juan Martin del Potro, the 2009 champion, became the lowest ranked player in 25 years to reach the quarter-finals.

The 142nd-ranked del Potro was leading eighth-seeded Dominic Thiem 6-3, 3-2 when the Austrian retired with a right knee injury.

Del Potro will face fellow Grand Slam title winner Stan Wawrinka for a semi-final spot.

Wawrinka, a former Australian and French Open champion, reached a fourth successive quarter-final with a hard-fought 6-4, 6-1, 6-7 (5/7), 6-3 win over Illya Marchenko, the world no. 63 from Ukraine.

Del Potro is playing just his second Grand Slam event since the 2014 Australian Open.

Earlier this year, he was on the brink of retirement after undergoing three wrist surgeries.

Sania-Strycova in quarters Sania Mirza and Barbara Strycova produced a solid performance against Nicole Gibbs and Nao Hibino to reach the women’s doubles quarter-finals. The Indo-Czech combine completed a 6-4 7-5 win over American-Japanese..

However, Rohan Bopanna and his partner Gabriela Dabrowski fought hard before losing their mixed doubles quarter-finals.

Bopanna and Dabrowski squandered a set advantage against Canadian Robert Farah and Anna-Lena Groenefeld of Germany before bowing out 6-1, 2-6, 8-10 in the super tie-breaker.