10:50 CET - Okay... Ready to do that again? As the tennis world continues to take stock of what just happened on the Rod Laver Arena, attention will soon turn to the second semi-final as holder Jannik Sinner takes on 10-time winner Novak Djokovic.

10:15 CET - Wow! The longest semi-final in Australian Open history has reached its conclusion after five sets of pure drama and somehow, someway, Carlos Alcaraz has come out on top!

The world number one was a break down for most of the deciding set, but broke Alexander Zverev back as the German was serving the match out and then broke him again to avoid a Championship tiebreak and book his place in Sunday's final.

Alcaraz defeated Zverev 6-4, 7-6 (5), 6-7 (3), 6-7 (4), 7-5.

Five and a half hours later and we finally have a winner...

08:55 CET - Well, well, well... Who saw this coming? Zverev has forced a fifth set decider after delivering another excellent tiebreak performance and a relentless set of serving. Can Alcaraz respond, or will the Spaniard finally meet his match?

07:52 CET - After edging past Zverev in the second set tiebreak, Alcaraz struggled with cramp in the third set and the German took full advantage to win the fourth set tiebreak 7-6 (3) to keep this semi-final alive. All to play for...

05:30 CET - A high quality first set of tennis goes Carlos Alcaraz's way as he takes it 6-4 over Alexander Zverev. The world number one seldom faced a break point in what was a near-flawless set. The break of serve came in the penultimate service game of the set. Follow the match on Flashscore.

04:50 CET - And we are off in the first men's semi-final between Carlos Alcaraz and Alexander Zverev. Follow all of the action on Flashscore.

00:00 CET - Welcome back to the Tennis Tracker in the early hours of Friday morning on men's semi-final day at the Australian Open!

Incredibly, we are left with the top four seeds still in the competition, meaning these match-ups are as good as it gets. Up first at 04:30 CET is a meeting between world number one Carlos Alcaraz and world number three Alexander Zverev.

The former has swept into the semi-finals without dropping a single set, as he continues his quest to become the youngest man in the Open Era to complete the Career Grand Slam. Meanwhile, the latter has also looked in great touch as he eyes his maiden major title.

Interestingly, the head-to-head between the pair is locked at 6-6, but a lot of Zverev's victories over Alcaraz came early in the Spaniard's career, with Alcaraz winning three of the last four meetings.

It could be a competitive match, but Zverev will have to serve lights out if he wants to win this last-four encounter.

That will be followed by the second semi between two-time defending champion Jannik Sinner and 10-time champion Novak Djokovic.

Sinner hasn't looked at his usual brilliant best in this tournament, as he has struggled with the heat, while Djokovic was extremely fortunate not to be dumped out after Lorenzo Musetti was forced to retire from their quarter-final after leading two sets to love.

Djokovic was also given a free pass into the quarter-finals after Jakub Mensik withdrew from their last-16 clash, meaning the Serbian great hasn't won a set since Saturday.

Taking into account Djokovic's age, how unconvincing he has looked, and the fact that Sinner is simply relentless in Australia and has won their last five meetings, it would be a major shock if the Italian didn't reach a third-straight final.