In the quarterfinals of the Australian Open, Novak Djokovic was determined to win a record 25th Grand Slam championship. His left leg is not an issue. No early deficit. And not Carlos Alcaraz, the boy on the other end of the internet, who was causing trouble and stealing his own piece of history.

In a thrilling match Tuesday night between two superstars who were born 16 years apart and at different stages of their careers, Djokovic overcame everything, as he has so frequently done on his path to so many victories, defeating Alcaraz 4-6, 6-4, 6-3, 6-4 to advance to the semifinals at Melbourne Park for the 12th time.

Even though the match lasted more than 3 1/2 hours and almost until 1 a.m., the action was constant and the shots were excellent. Perhaps this was never the case more than in the fourth set, when Alcaraz saved a break point that would have given Djokovic a 5-2 lead and let him serve for the victory.

Rod Laver Arena’s full audience went berserk as the evening’s longest exchange, which lasted 33 strokes, finished with Djokovic floating a forehand long.

Alcaraz, his chest heaving, leaned on a towel box and smiled as Djokovic grabbed his annoying leg and shouted at his group. That just served to postpone the outcome.