Melbourne, 21 Jan

Novak Djokovic refused to let anything stop his pursuit of a record 25th Grand Slam trophy in the Australian Open quarterfinals. Not a problem with his left leg. Not an early deficit. And not the kid across the net, Carlos Alcaraz, who was making things difficult and eyeing his own bit of history.

Djokovic overcame it all, just as he has so often along the way to so many triumphs, moving into the semifinals at Melbourne Park for the 12th time with a 4-6, 6-4, 6-3, 6-4 victory over Alcaraz in a scintillating showdown Tuesday night between a pair of stars born 16 years apart and at opposite ends of their careers.

The action was non-stop, the shot-making brilliant, even as the match stretched on for more than 3 1/2 hours and nearly to 1 a.m. — never more so, perhaps, than when Alcaraz saved a break point that would have put Djokovic ahead 5-2 in the fourth set, allowing him to serve for the win. The 33-stroke exchange was the longest of the evening, and when it ended with Djokovic sailing a forehand long, the capacity crowd at Rod Laver Arena went wild. Djokovic reached for his bothersome leg and yelled toward his entourage; Alcaraz, his chest heaving, leaned on a towel box and grinned.

Turned out that only delayed the final result.

With his wife, son and daughter cheering in the stands, the No. 7-seeded Djokovic prevailed thanks to the sort of remarkable returning and no-mistakes-made groundstrokes against Alcaraz that now-retired rivals Roger Federer and Rafael Nadal dealt with for years.

Djokovic enjoyed some of his own best efforts in the latter stages, pointing to his ear or blowing kisses or spreading his arms while puffing out his chest. There was the forehand winner on a 22-stroke point that earned the break for a 5-3 lead in the third set. There was that set's last point, which included a back-to-the-net sprint to chase down a lob. Alcaraz wasn't shy, either, shouting “Vamos!” and pumping his fists after one particularly booming forehand in the fourth set.

On Friday, Djokovic's 50th major semifinal will come against No. 2 seed Alexander Zverev, a two-time runner-up at majors who beat No. 12 Tommy Paul 7-6 (1), 7-6 (0), 2-6, 6-1. The other men's quarterfinals are Wednesday: No. 1 Jannik Sinner vs. No. 8 Alex de Minaur, and No. 21 Ben Shelton against unseeded Lorenzo Sonego.