Melbourne (AFP) - Novak Djokovic on Tuesday won a generational clash against Carlos Alcaraz at the Australian Open that he said was worthy of the final to close in on a record 25th Grand Slam title with Alexander Zverev next up in the last four.

The 37-year-old Serb outlasted the Spaniard, 16 years his junior, 4-6, 6-4, 6-3, 6-4 despite having his left thigh heavily strapped.

It was a vintage 3hrs 37mins performance and put him into the last four at Melbourne Park for a 12th time, with only Roger Federer (15) doing so more often.

The win also extended his all-time record for most Grand Slam semi-final appearances to 50, four clear of the Swiss great.

To reach another final he will need to beat second seed Zverev, who battled into the semis for a second year running with a 7-6 (⁷⁄₁), 7-6 (⁷⁄₀), 2-6, 6-1 win over American 12th seed Tommy Paul.

“I just wish that this match today was the final,” said 10-time Melbourne champion Djokovic.

“Just one of the most epic matches I have played on this court, any court really.”

“I guess the key is recovery,” he added, looking ahead to the Zverev clash.

“That’s all I’m thinking about. Hopefully I can come out and feel my best because Sascha (Zverev) is playing some of the best tennis he has played.”

As the wind swirled, Djokovic opened with a commanding hold then broke immediately as the 21-year-old Alcaraz struggled to find his range.

But the advantage was short-lived with the world number three rifling a backhand down the line to break straight back.

Seventh seed Djokovic saved two break points in an enthralling game nine, but appeared to be wincing and Alcaraz converted on the third for a 5-4 lead when the veteran sprayed a forehand wide.

The Serb called the trainer and left court for a medical timeout after the game, with Alcaraz sealing the set to love on his return.

But Djokovic, with his thigh now strapped, wasn’t done and broke to race 3-0 ahead in set two, playing more aggressively.

Alcaraz then won three games in a row to seemingly seize control, but Djokovic pulled off a break to love from nowhere with a backhand winner to take the set.

The third set went with serve until three breaks in a row left Djokovic 5-3 ahead and able to serve out, blowing kisses to his children in the crowd.

Djokovic had all the momentum and broke straight away in the fourth set. Both men produced some sensational tennis, including a 33-shot rally, before Alcaraz finally succumbed.

Djokovic refused to say exactly what his injury problem was, but said “the medication started to kick in, and it helped”.

He conceded: “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.”

- The greatest -

Zverev edged closer to his dream of a maiden Grand Slam title.

The German also reached the semis in 2020, losing to Dominic Thiem, and again last year when he crashed to Daniil Medvedev in five sets despite holding a 2-0 lead.

He has played Djokovic 12 times before dating back to 2017, with the Serb holding an 8-4 record, including victory when they last met, in 2023 at Cincinnati.

“Two of the best players that have ever touched a tennis racquet,” said Zverev of Djokovic and Alcaraz.

“Novak is the greatest of all time right now. Carlos is going to be one of them when he hangs it up so it is a clash of generations.”

Bidding to become the first German man to win a Grand Slam since Boris Becker in 1996, Zverev was made to work hard by Paul.

But he asserted himself when it mattered in the tiebreaks and won the fourth set emphatically.

“I’m going to prepare myself for a very intense and high-level match,” he said on the semi-final.