Aslan Karatsev's nickname is 'the Lion', and with good reason.
The Russian had to dig deep and then a bit deeper to roar back from 6-3 3-0 down to world No.70 Jaume Munar in the opening round at Australian Open 2022 on Monday.
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Finally, after four hours and 52 gutsy minutes, the 28-year-old closed out a rock n' roll 3-6 7-6(1) 6-7(3) 6-4 6-4 epic. After 87 winners and 107 unforced errors, he was simply too exhausted to celebrate.
Karatsev will do whatever it takes, personifying perseverance along the way.
"It wasn't difficult to go five hours. That's not the mindset," he insisted, taking such a brutal battle in his stride.
"You think you have to find the key, the solution for your game to try to win the second set and then you keep going every point you think 'Okay, next point, next point' and then somehow I found the rhythm," analysed the 28-year-old, who simply won't back down.
"I just keep trying to find any solution. I don't care if I don't feel the ball, but in the end I want to win so as to find any solution or the right key for the match."
We shouldn't be surprised. After all, the Russian is back on a familiar happy hunting ground.
Karatsev was one of the breakout stars of 2021, and it all started back at Melbourne Park to reach the semifinals. Just last week, he returned to ferocious form to claim the silverware at the Sydney Tennis Classic.
Something clicks for Aslan in Australia.
"I like to play here. Especially, it's a start of the year, you're fresh in good mood, good energy," added the Russian, explaining his comfort in these surroundings after a promising off-season in Spain at the 4Slam Tennis Academy.
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Last January he arrived Down Under ranked No.114, with a 3-10 record at Tour level and without a clothing sponsor. Only the truly dedicated tennis fan would know of his back story of injuries and tussles on the Challenger Tour.
The resolute Russian rattled through qualifying before one of the most astonishing runs in modern times at Melbourne Park.
In devastating form, his gunpowder brand of tennis scorched 50 winners past world No.9 Diego Schwartzman, and in the fourth round he reeled in Canada's Felix Auger-Aliassime from two sets down.
"That was a tough match against Aliassime, from two-zero down that was really tough mentally, physically," he said.
"So, I think that was my highlight from last year here."
By now the tennis world was obsessed with Karatsev, how this rock-solid Russian had never featured at the top table.
It wasn't ending there.
He downed Grigor Dimitrov in four sets to earn a semifinal shootout with the world No.1 and defending champion Novak Djokovic.
After a straight-sets dismissal, Karatsev could take plenty of pride as the first man in the Open Era to reach the semifinals on his Grand Slam debut. He was also the first qualifier to reach an Australian Open semifinal since Bob Giltinan in 1977. There were a lot of "firsts" for Aslan.
Just like a five-hour thriller or taking on the world No.1, nothing fazes the Lion, even having to defend his final-four haul of 720 ranking points this January.
"I wish to defend every Slam semifinal or more. You can't just arrive to Grand Slam and to think 'oh, I have to defend'," he insisted.
"But yeah, just playing every match. First of all, you have to play what you were practising, and then we'll see what's going on the court. I'm trying not to think about it."
Karatsev was far from a flash in the pan. Two tour-level titles followed in Dubai and Moscow. He also downed Djokovic in Serbia 7-5 4-6 6-4 at the Belgrade 1 event en route to the final. Karatsev even won an Olympic medal, going silver alongside Elena Vesnina at Tokyo 2020.
He kept picking up results and was rewarded with a career-high ranking of No.15, which he plays with at AO 2022.
Struck down by Covid, Karatsev's preparations for a return to Australia this year were hampered. Again, no problem. He demonstrated why he is an established member of the world's top 20 to lift his third title in Sydney.
Two matches stand out. A hot-shot laden 6-3 6-7(13) 6-3 victory over world No.24 Dan Evans was backed up by a dominant 6-3 6-3 passage past former world No.1 Andy Murray.
James Blake was the last Sydney champion to reach the Australian Open second week in 2007, but that won't disrupt the tunnel vision of Karatsev.
"I know he also arrived late in Australia recovering from Covid, so it's even more impressive to come back straightaway at that level," said Murray back in Sydney.
If five-time Australian Open finalist Murray is impressed, then Aslan the Lion is on the right path to hunt down the pack once again.