Murray tearfully announced on Friday that he is planning to retire this year, and maybe as soon as after this tournament, but the 31-year-old still threatened a shock but was ultimately beaten 6-4 6-4 6-7 (5) 6-7 (4) 6-2 by the Spanish 22nd seed.
Murray’s hopes were not high given the state of his right hip but this was a remarkable performance for a man who admits he struggles to put his shoes and socks on.
A kinder draw and Murray might well have delayed the seemingly inevitable but Bautista Agut is one of the fittest and grittiest players on tour, and he fought off the Scot’s comeback.
The snaking queues outside Melbourne Arena of tennis fans wanting to see Murray was a sight to behold and he was greeted by a deafening roar as he emerged onto the court, which has seats available to holders of ground passes.
Murray waved and held a thumb up, no doubt determined to soak it all in.
His coaching team, Davis Cup captain Leon Smith, friend and former coach Dani Vallverdu, British players Katie Swan and Harriet Dart and mum Judy were among those in attendance and they were joined during the opening set by brother Jamie, who rarely watches Andy live because he finds it too stressful.
If that was an indication this was far from just another match, the early stages were encouraging, with Murray moving much better than he had in Thursday’s practice match against Novak Djokovic that set the alarm bells jangling.
He was striking his backhand well but movement to the forehand remained a major issue and the ever-present limp slowly became more pronounced.
It was a tough situation for Bautista Agut, taking on the crowd and an opponent who was clearly not at full fitness but whose capabilities on the day remained a question mark.
The Spaniard took the first set after breaking at 4-4 and Murray’s chuntering to himself was a reminder that he still very much wanted to win a tennis match.
There were flickers early in the second set with two break points but Bautista Agut went on to take that too.
It would not be Murray, though, if he did not go down without a fight, and fight he did.
Broken for 1-2 in the third set, he hit straight back, pushing a backhand down the line to finish a vintage point before holding his arms aloft.
There were more celebrations when he fought off a break point at 4-4, and he forced a first set point in the next game. He would have taken it, too, but for an overrule from umpire Eva Asderaki-Moore on a second serve that was backed up by HawkEye.
But Murray was not to be denied in the tie-break, creating two set points when Bautista Agut shanked a forehand over the baseline and taking the second with a forehand guided into the open court.
Murray roared in delight and defiance, his fighter’s instinct drowning out the pain.
And the heroics did not end there. Murray matched Bautista Agut throughout the fourth set and was the better player in the tie-break. But he was unable to maintain his momentum early in the fifth set, with Bautista Agut winning five games in a row.
Murray fought back tears as he served at 1-5 but there was still time for one more magic moment as he saved a match point by finishing a long rally with an angled volley winner. Murray was relieved to finally reveal the severity of his struggles and was left stunned by the reaction.
“Once I chatted to you guys, although it was difficult for me, I felt a lot better because, for the last 18 months, I was struggling a lot,” he said.
“When you’re going to compete, you want to be positive and optimistic about things because you don’t want to be telling your opponents how bad you’re feeling. That was the first time I came out and let everyone know how bad it’s been, and (how) tough. I felt a lot better after that. But obviously the reaction, I was really surprised by. I genuinely was not expecting it to be like that at all. It was really nice.”