Andy Murray's brave Australian Open run ground to a halt against Roberto Bautista Agut, the Spaniard fending off the fatigued former world number one 6-1 6-7(7) 6-3 6-4 in the third round to advance on Saturday.

After back-to-back five-set wins over Matteo Berrettini and Thanasi Kokkinakis, a ragged Murray hung tough against the 24th seed but was gradually worn down over the course of a three-and-a-half hour slog at a floodlit Margaret Court Arena.

Murray's previous match against Kokkinakis, which ended past four in the morning after nearly five hours of play, left him with little sleep, a bad back and a slew of blisters that needed draining in his feet.

"My feet didn't feel great. My legs were actually OK ... but I was struggling with my lower back," Murray told reporters. "That was affecting my serve and that was really the main thing today."

It has been a long and punishing road back for the three-times Grand Slam champion since being fitted with a metal hip. But he was encouraged by his week at Melbourne Park, if disappointed not to reach the second week.

Novak Djokovic’s hamstring just about held up as the hot favourite battled into the Australian Open last 16 on Saturday. An ailing Djokovic had heavy strapping and needed treatment twice on his troublesome left hamstring before defeating Grigor Dimitrov 7-6 (9/7), 6-3, 6-4 on Rod Laver Arena, setting up a quarterfinal with Alex de Minaur as he closes on a 10th Melbourne Park crown and a record-equalling 22nd Grand Slam title. Photo: REUTERS

"Lots of mixed emotions, I feel like I gave everything I had to this event, so I'm proud of that," he said. "But, yeah, I'm also disappointed because I put loads of work into the beginning of this year and was playing well enough to have a really good run, have a deep run. I'm disappointed because I feel like I could have gone quite a bit further."

Earlier, an ailing Novak Djokovic said every moment counted now that he was in the "last stage" of his career, after battling past Grigor Dimitrov 7-6 (9/7), 6-3, 6-4.

Djokovic needed treatment twice on his troublesome hamstring.

"Every season counts I guess now, when you come to the last stage, the last quarter, of your career," the 35-year-old said. "Obviously you start appreciating and valuing each tournament more because you might not have a lot left in the tank.

"I've been truly fortunate to do what I love, I love the sport, I love competing. It's been almost 20 years now of professional sport. I can't be more grateful than I am."