Novak Djokovic said he chose to turn to Andy Murray after beating Carlos Alcaraz in the quarter-finals of the Australian Open as a “gesture of appreciation” for his coach.

Djokovic defied an upper leg injury to defeat Alcaraz in four sets in a battle the 10-time champion described as one of the fiercest he has fought in Melbourne.

After winning match point at nearly 1am, Djokovic turned to his coaching box and roared directly at Murray before shaking hands with Alcaraz at the net.

Djokovic appointed former rival Murray as his coach for the Australian Open and this was the partnership’s most significant moment yet.

Djokovic and Murray also hugged on the Rod Laver Arena as the 37-year-old took a step closer to winning a record 25th grand slam title this month.

“I feel more and more connected with Andy every day,” Djokovic said after the 4-6 6-4 6-3 6-4 win. “We face challenges every single day. People don’t see that obviously.

“We try to make the most out of every day and grow together. He’s been as committed to my career and this tournament as he can be.

“So it was kind of a gesture of appreciation, respect for him, and the fact that he’s out there, and he doesn’t need to be.

“He accepted to work with me. He’s giving all his support to me, to the whole team, and trying to make it work. This was a huge win for all of us, including Andy and myself.”

Meanwhile, Djokovic admitted he is “concerned” by his left leg injury as attention now turns to Friday’s Australian Open semi-final against second seed Alexander Zverev.

He was forced to take a medical timeout towards the end of the first set and admitted he may have quit had he not won the second set, before the painkillers started to work.

“I have to assess the situation tomorrow when I wake up,” Djokovic said. “I will try to do as much as I possibly can with my recovery team, with my physio today, tomorrow, the next few days. Probably skip training tomorrow.

“I’ll see if I’m going to train in two days or not. I’ll take it day by day. Now it’s really about recovery.

“I’m concerned. I am, to be honest, physically. But if I manage somehow to be physically good enough, I think mentally, emotionally I’m as motivated as I can be.

“This match drains both players. Almost three and a half, four hours of incredible battle, of high intensity, of course it has its toll.

“At the same time I think it has more toll on the physical side rather than mental and emotional. Actually it feels like you’re feeding off this kind of win.

“That’s how I feel now. I hope to be able physically to be moving freely and to be able to be ready to play five sets.”