Novak Djokovic Defeats Alexander Zverev to Advance to 2021 Australian Open Semis

Top-seeded Novak Djokovic survived a tough challenge from No. 6 Alexander Zverev in the Australian Open quarterfinals on Tuesday, winning 6-7 (6), 6-2, 6-4, 7-6 (6) to advance to the semis in Melbourne.

With the win, Djoker has now reached nine Aussie Open semifinals during his career, and he has made it to the semis or better three straight years at Melbourne Park.

By virtue of his victory over Zverev, Djokovic will face Russian qualifier Aslan Karatsev in the semifinals, giving Nole a clear path to the final and perhaps his ninth career Aussie Open title.

While Tuesday's match didn't quite go the distance, it was a marathon nonetheless, as Djokovic needed three hours and 30 minutes to dispatch his toughest challenge in this year's Aussie Open to date.

Djoker played from behind for much of the match, and it started in the first set when Zverev beat him in a tiebreak to put the pressure on the reigning Australian Open champion.

Although Djokovic battled back to win the second set handily, there was more frustration to come.

Zverev jumped out to a commanding 4-1 lead in the third set, and in the midst of his poor play, Djokovic destroyed his racket:

The German upstart seemingly had Djokovic right where he wanted him at that point, but Nole collected himself and the experience on the big stage served him well, as he reeled off five games in a row to win the third set 6-4 after trailing 4-1.

Despite the letdown, Zverev once again got off to a hot start in the fourth set, as he broke Djokovic and took a 3-0 lead.

Just as it did in the previous set, however, that lead quickly evaporated, as Jose Morgado of Diario Record pointed out:

The rest of the fourth set after Djokovic tied it was essentially a stalemate, which resulted in a second tiebreak. The result was different this time, however, with Djoker outlasting Zverev to win the match.

Tuesday's win improved Djokovic's career record at the Australian Open to 80-8, and it also put him in a Grand Slam semifinal for the 39th time in his career.

In the previous 38 trips to a Grand Slam semi, Djokovic turned 17 of them into major titles.

Djokovic has never failed to win the Australian Open when making it to at least the semifinals:

He was pushed to the limit in many ways, as he absorbed 45 winners and 21 aces from the powerful Zverev, and he also overcame making 56 unforced errors.

It was far from a clean match for Djokovic, but his opportunistic nature was the difference-maker, as he converted six of nine break points, while Zverev came through on just three of 12.

Djokovic will be a heavy favorite in the semis when he faces Karatsev, the first man in the Open era to reach the semifinals in his Grand Slam debut.

The 27-year-old Karatsev has beaten some notable names en route to the semis, including Diego Schwartzman and Grigor Dimitrov, but to extend his Cinderella run, he will have to beat one of the greatest of all time.