Andy Murray made a first-round exit from the Brisbane International as Grigor Dimitrov came from behind to win in three sets.

The defeat is a setback for Murray's preparations for the Australian Open, which starts on 14 January.

It comes after the Briton said the 2024 season could be his last on tour if he is "not enjoying it".

The 36-year-old struggled with a shoulder injury in the latter months of 2023, while illness and a bruised knee made for what he described as a "tricky" pre-season in an interview with BBC Sport before the Brisbane event.

Playing in his first competitive singles match since October, Murray came out on top of a tight first set that went with the serve, sealing the opener on its only break point after an error-strewn Dimitrov service game.

More comfortable holds for both players followed, with Dimitrov eventually edging ahead in the ninth game - the first of the set to feature break-point opportunities.

Although Murray - a two-time champion in Brisbane - cancelled it out immediately, Dimitrov broke again before saving two break points, including one with a broken string, on his way to sealing the second set.

In the third, the world number 14 raced to a 4-0 lead, and while Scot Murray slowed Dimitrov's pace despite issues with his racquet, he could not convert a break point at 5-2 from which his opponent held.

"I've really missed this tournament," said 2017 champion Dimitrov, who will face German Daniel Altmaier or Australian qualifier Li Tu in the second round. "Here we go, kicking off the new year in style.

"I just wanted to carry [last season] on. Of course it's never easy, especially when you're playing so well at the end of the year, you put pressure on yourself to start well.

"As soon as I came out here today, I felt a little rusty to be honest. I have to keep on fighting, I have to keep on believing in the work that I've put in."

Before the Australian Open, Murray will play the Kooyong Classic exhibition in Melbourne next week.