British tennis ace Andy Murray has pulled out of the ATP Washington Open after a gruelling 3am victory that left him sobbing on the court.

Citing fatigue, the three-time Grand Slam winner withdrew on Friday (local time) after an early morning win against Romanian Marius Copil, giving Australian Alex de Minaur a clear berth in the semi-finals.

Murray, who returned from injury in June after an 11-month absence, blamed the midnight start and a succession of tough matches for his decision to throw in the towel.

Following the 6-7 (5), 6-3, 7-6 (4) victory against Copil, Murray spent several minutes sobbing into a towel before announcing that he was withdrawing from the competition.

The 31-year-old Scotsman also announced he would not be taking part in next week’s ATP Toronto Masters as scheduled.

“I’ve had a few long matches. Finishing matches at three in the morning isn’t good for anyone involved in the event, players, TV, fans, anyone,” he said.

“When you’re expected to come back and perform the next day, I think that’s unreasonable.

“It’s a very difficult position to be coming back from a long injury to be finishing matches at 3 o’clock in the morning. By the time you finish doing recovery and everything it’s 5.30 or 6 o’clock in the morning.

“… I need to be smart with my rest and recovery as I come back from injury,” Murray said.

Watch Andy Murray’ break down after 3 am finish

Commentator and former grand slam champ Jim Courier said Murray’s emotional and exhausted reaction was “a beautiful thing to see”.

“That is what it’s all about, right here,” Courier said.

While Murray’s response attracted a degree of ridicule, it also garnered a great deal of admiration on social media.

Go @andy_murray 💪💪💪 this is what love for sport is! @JudyMurray ❤️❤️❤️❤️ https://t.co/gwep7us7XP

— Jelena Djokovic (@jelenadjokovic) August 3, 2018

No words, @andy_murray.

Just thanks for your emotions… 😍🙏#CitiOpen pic.twitter.com/w89E3sCzJg

— Tennis TV (@TennisTV) August 3, 2018

@Andy Murray, Congratulation for showing us that champions like patients, executives and objective reviewers cried to be healthy, happy and more.  Crying is in our DNA according to a magazine written by a physiatrist.   https://t.co/qk9drGPsxO

— April Tan (@AprilLeads) August 3, 2018

Murray’s surprise withdrawal handed 19-year-old Sydneysider de Minaur automatic passage to the semi-finals.

Also on Friday, defending champion Alexander Zverev advanced to the semi-finals after a 3-6 6-1 6-4 victory over No. 7 seed Kei Nishikori.  Zverev will face Stefanos Tsitsipas of Greece on Saturday.

-With AAP