The Scot threatened an incredible comeback from two sets down but eventually lost in five to Spain's Roberto Bautista Agut in the first round in Melbourne.

Having suffered with a long-standing hip injury since 2017, three-time Grand Slam champion Sir Andy announced his intention to retire this season last Friday (January 11) and said the year's first Grand Slam could be his final tournament.

Unseeded, he was drawn against 30-year-old Bautista Agut in round one at Melbourne Park and was widely expected to lose, but the match ended up much tighter than anyone anticipated, eventually ending 4-6, 4-6, 7-6, 7-6, 2-6.

Against the odds 31-year-old Murray started the match brightly, with the first set initially going on serve.

The Spaniard, who is currently ranked 24th in the world, did eventually find a break though to take the set 6-4.

The second set followed a similar script, with Scotland's two-time Olympic gold medallist Murray playing some world class tennis at times but failing to take the key points.

With Bautista Agut two sets up and Murray clearly in pain after long rallies, a fightback seemed highly unlikely, if not impossible, but refusing to roll over the Scot crawled his way back into the match and through two tiebreaks eventually levelled it at two sets all.

Having expended so much energy to bring the match level Murray then struggled to maintain his performance in the fifth and was broken twice to lose 6-2.

Bautista Agut will now play Australia's John Millman in round two.

"If this was my last match, it was an amazing way to end," Murray said.

"I gave everything I had - it wasn't enough tonight."

He added, however, that despite all the retirement talk he could have another operation to try and keep playing.

"Maybe I'll see you [the Australian Open crowd] again," he said.

"I'll do everything possible to try.

"If I want to go again, I'll need to have a big operation, which there's no guarantee I'll be able to come back from anyway, but I'll give it my best shot."

Elsewhere on the first day of play 20-time Grand Slam champion Roger Federer - who turns 38 this year - beat Uzbekistan's Denis Istomin 6-3, 6-4, 6-4, while 17-time Grand Slam champion Rafael Nadal beat Australian wildcard Jamie Duckworth 6-4, 6-3, 7-5.

Serbia's current world number one and top seed Novak Djokovic begins his campaign tomorrow.

In the women's draw the 2017 French Open champion Jelena Ostapenko of Latvia crashed out against Maria Sakkari from Greece 1-6, 6-3, 2-6.

Generally speaking women's results went as expected, with 2017 US Open champion Sloane Stephens winning an all-American clash with Taylor Townsend 6-4, 6-2.

Defending Australian Open champion Caroline Wozniacki of Denmark saw off Alison Van Uytvanck of Belgium 6-3, 6-4.

Five-time Grand Slam champion Maria Sharapova of Russia whitewashed Britain's Harriet Dart 6-0, 6-0.