Towards the end of his fourth set with Australian player Thanasi Kokkinakis in the Australian Open second-round match on Thursday, the current world No. 66 was fuming at umpire Eva Asderaki-Moore over the bathroom break rules after forcing a fifth and final set.
Murray's match with Kokkinakis has lasted over five hours, reaching into the wee hours of 3am Melbourne time.
In footage shared by Eurosport's official Twitter account, the five-time finalist can be seen calling the moment "disrespectful" as players can't go use the toilet more than once following rule changes.
"It's a joke. It is a joke, and you know it," Murray can be seen telling Asderaki-Moore, who nodded her head in acknowledgement.
Murray added: "It's disrespectful. It's disrespectful to you, it's disrespectful to the [sic] children, it's disrespectful to the players, and we're not allowed to go to the toilet – it's ridiculous."
\u201c"It's a \ud835\udc23\ud835\udc28\ud835\udc24\ud835\udc1e... It's \ud835\udc1d\ud835\udc22\ud835\udc2c\ud835\udc2b\ud835\udc1e\ud835\udc2c\ud835\udc29\ud835\udc1e\ud835\udc1c\ud835\udc2d\ud835\udc1f\ud835\udc2e\ud835\udc25!" \ud83d\ude21\n\nAndy Murray is furious for not being allowed a bathroom break at the end of the fourth set during his late-night encounter against Thanasi Kokkinakis... \n\n#AusOpen | @andy_murray\u201d
Once people online saw this exchange, they echoed Murray's sentiments, noting that it seems odd not to allow players to use the bathroom, especially when they've been playing for over five hours.
One person on Twitter wrote: "It seems ludicrous to me that this isn't permitted after 5 hours at 3am."
"How can players not be entitled to a toilet break after 4hrs of play and 5 sets? Like, what's the issue the umpire has with the request?" another added.
A third wrote: "@andy_murray is completely justified in his frustration. How can going to the toilet not be allowed?#AusOpen."
However, despite the lack of a bathroom break, Murray fought back from two sets down in his match with Kokkinakis, cementing his place in the third round of the Australian Open.
Murray, a former No.1 and five-time finalist, beat Kokkinakis 4-6, 6-7(4), 7-6(5), 6-3, 7-5.
The pairs encounter finished after 4am, lasting 5 hours and 45 minutes in the longest match of Murray's career.
\u201c35yo Andy Murray, a former world #1 with a metal hip, who played 5h two days ago, comes back to beat Thanasi Kokkinakis 4-6, 6-7(4), 7-6(5), 6-3, 7-5 in the 2nd longest ever #AusOpen match: 5h45, finished after 4am in the morning.\n\nInto the 3rd round\n\nEpic. Legendary. All of that\u201d