Novak Djokovic is through to another Australian Open semi-final but his dramatic win over Alexander Zverev has left us with more questions than answers.
This was far from a vintage performance from the king of Melbourne Park, who was all over the shop at different stages of the match and endured wild mood swings en route to an incredibly gutsy 6-7 6-2 6-4 7-6 victory.
Speaking after his third round win over Taylor Fritz, Djokovic revealed he was suffering from an abdominal "muscle tear" — yet showed no signs of discomfort as he overcame the American in five sets.
The world No. 1 remained coy on his physical condition after beating Milos Raonic in round four, but said his injury was so bad he would have pulled out of the tournament if it wasn't a grand slam.
Djokovic has a reputation among tennis fans for concocting injuries to explain away losses and over-exaggerating physical ailments during matches when the ledger is against him — so not everyone was willing to buy his story.
Even Rafael Nadal and his uncle Toni thought the Serbian was telling porkies.
But there was undeniably something off with Djokovic against Zverev — who suffered distractions of his own ahead of the match when the woman carrying his child unloaded — even if his will to win eventually saw him outlast the German, who is still without a win over a top 10 player at a grand slam.
Djokovic was out of sorts in the opening set. The best defensive player we've seen, who has perfected the art of grinding down opponents in long baseline rallies on the blue hard courts of Melbourne Park, was missing.
Instead, the 17-time major winner was looking for quick, cheap points, and he made a stack of uncharacteristic unforced errors. Anyone doubting his injury concerns needed only to look at this set for evidence that Djokovic was indeed struggling big time with his body.
"With this kind of condition I need time to warm up," Djokovic said post-match when explaining his opening set woes.
"Even though I had almost an hour of a warm-up hit prior to the match … I still felt like it's going to take me some time to warm up to actually feel that I can rotate well."
Then came the second set, and it was like the 33-year-old had sipped a magical elixir. Gone was the grimacing and hobbling as Djokovic raced to a 4-0 lead in less time than it took Zverev to win the first set tie-break.
Maybe Djokovic was foxing after all?
Whatever was going on, soon Djokovic's spirit looked broken, even if his body wasn't, as more momentum swings changed the course of the quarter-final. Down 1-3 in the third set, Djokovic cut a miserable figure as he slumped against the back wall while he waited for Zverev to return to the court.
Mentally and physically, he seemed cooked. Was playing through the pain becoming too much?
The top seed raged at team members in his player's box and smashed a racquet so badly a ballkid needed to sweep up pieces that had scattered around the court.
Remarkably, that outbreak of emotion sparked Djokovic into action. He won 16 of the next 19 points and ended up going ahead.
The fourth set was just as mysterious. As Zverev went up a break at 2-0, Djokovic threatened to once again smash his racquet but pulled back at the last second, then yelled at his entourage.
At 1-3 he glared at his team and continued with a death stare — but what he was trying to achieve was anyone's guess.
He rebounded for 3-3 and had enough gas in the tank to engage in gruelling rallies with Zverev as he eventually wore down his younger rival in a final tie-break.
If anything, at times Djokovic's his mental application appeared to suffer more from any physical injury than his body did.
"Novak — not a great example for kids but quite an amazing level of fury considering his stomach muscle injury," Channel 7's Adrian Barich tweeted.
Gerald Butts added: "I see Novak Djokovic has made another miraculous recovery from another devastating injury."
Nadal said it would be "impossible" for anyone to win a grand slam with the type of injury Djokovic has described. But the eight-time Australian Open champion wasn't backing down.
"No," he said when asked if he's ever had an injury during a grand slam as bad as this. "I've
been doing various things to try to put myself in a condition to play.
"I haven't been practising in the days off. I am going to keep doing the same and hopefully the result will be in the end the same like it was today."
The win over Zverev — or more accurately, the way he won — has only made things murkier. Either Djokovic isn't suffering as badly as he wants everyone to believe, or he's so good that he's two wins away from proving Nadal and Co. wrong by defying all logic to successfully complete Mission Impossible, banged-up body and all.