The 23-year-old Italian only made it through four more points before, looking forlorn, he gingerly walked to the net to shake hands with Djokovic and exit the Open.
Djokovic said he only became aware that Musetti was hampered in what became the final set of the match.
“Honestly, the first time I saw him struggling a bit was in the third game of the third set when I broke his serve,” said Djokovic.
“I didn’t feel that in the second set it was affecting his game much.”
The Serbian had also battled with a blister on his right foot, but he said it didn’t overly affect his performance.
“You always have some minor issues with your body, at least for me every single day, [but none stopping me] be able to play and move around the way I want to,” Djokovic said.
Straight after his stroke of luck, in his on-court interview, Djokovic said: “I’m going to double my prayers tonight for sure, [and show] gratitude to God for giving me this opportunity once again.
“I’m going to do my best in a couple of days to use it.
“Today I’m definitely not happy with my performance but … in a couple of days hopefully I can come out and be at my best because that’s what is needed.”
The Serb returned to action after an extended break after fourth-round opponent Jakub Mensik’s walkover on Sunday, and his freshness showed at different stages of the match.
“I had four winners in the first two games and no unforced errors, and then the rest of the match I had another four winners and probably 40 errors. That’s what Lorenzo does to you, [he] makes you play when you think the point is finished,” Djokovic said.
“When you attack him, you don’t know what to expect – whether it’s going to be a passing shot, a cross-court or a short slice, or if he’s going to go full flat in your body or hit a looping ball to my weakest shot, which is overhead.
“I tried my best … I wasn’t feeling the ball today the first couple of sets, but that’s also due to his quality and his variety in the game. I’m extremely lucky to get through this one.”
Before Wednesday’s final-eight showdown, Djokovic had spent just six hours and 59 minutes on court. In contrast, Musetti spent more than 12 hours on court. Musetti’s first-round opponent, Raphael Collignon, retired in the fourth set of their clash. The Italian then needed five sets to beat Tomas Machac in the third round, and he saw off an injury-hit Taylor Fritz in the fourth round.
With the quarter-final result on centre court – in two hours and eight minutes – Djokovic recorded his 103rd Australian Open singles win, eclipsing Roger Federer’s record.
A bitterly disappointed Musetti walked gingerly into his media conference before explaining that he first felt the injury the after the first set, and it got progressively worse.
Musetti was on fire until injury struck in the cruelest way.Credit: Chris Hopkins
“I felt there was something strange in my right leg. I continued to play, because I was playing really, really, really well, but I was feeling that the pain was increasing, and the problem was not getting away,” he said.
“At the end, when I took the medical timeout … I [sat down] and when I started to play again, I felt [it] even more and [it] was getting higher and higher, the level of the pain.”
The two-time major semi-finalist said it was likely a muscle tear, high on his leg. Asked to pinpoint the exact spot, Musetti said: “I’m not [a] doctor, but it’s kind of on the… I don’t know if it’s the adductor, or… I don’t know.”
Wednesday’s dramatic events mark just the latest chapter in Djokovic’s remarkable relationship with Melbourne and the Australian Open. He won his first major on Rod Laver Arena 18 years ago and, since 2011, the 24-time major winner has had an extraordinary success rate.
Outside of a shock second-round loss to Denis Istomin in 2017, a fourth-round exit to South Korea’s Chung Hyeon the following year, and an epic quarter-final loss to eventual champion Stan Wawrinka in 2014, Djokovic has reached the semi-finals or better every year at Melbourne Park since.
While he was deported from Australia four years ago on tournament eve – dramatically preventing him from a shot at another Australian Open title – Djokovic’s record at the first major of the year has drawn similarities to that of Rafael Nadal’s 14 wins at Roland-Garros.
