- Won the French Open in 1989 as a teenager
He stunned tennis fans after winning a Grand Slam aged 17 before becoming a force on the professional tour alongside compatriots Pete Sampras, Jim Courier and Andre Agassi.
The tennis star also reached a career-high ranking of No.2 in the world in 1996 – and was a fan favourite due to his tenacity on court.
After retiring from the circuit in 2003, the player in question – who is a Hall of Famer – eventually turned his attention to coaching, notably with Japanese star Kei Nishikori.
In July last year, the sporting great began working with US rising star Learner Tien, a quarter-finalist at this year’s Australian Open.
The mystery man is, of course, Michael Chang.
And even though Alexander Zverev beat the Chang-coached Tien, 20, in four sets on Tuesday to set up a semi-final showdown with Carlos Alcaraz, the German acknowledged the American is one to watch in 2026 and beyond, thanks in no small part to his famous mentor.
Michael Chang (pictured, coaching at the Australian Open) stunned tennis fans after winning a Grand Slam aged 17 before becoming a force on the professional tour alongside compatriots Pete Sampras, Jim Courier and Andre Agassi
Chang reached a career-high ranking of two in the world in 1996 – and was a fan favourite due to his tenacity on court
In July last year, Chang began working with US rising star Learner Tien, a quarter-finalist at this year’s Australian Open
‘Learner from the baseline was playing unbelievable,’ Zverev said post-match.
‘I don’t think I’ve played anyone who plays that well from the baseline for a very, very long time.
‘I don’t know what (coach) Michael Chang has done with him in the off-season, but the way he’s playing, it’s incredible.
‘Without my 20 aces, or something like that, I don’t think I would have won.’
Tien also won plenty of admirers after stunning Daniil Medvedev in straight sets earlier in the tournament.
The 25th seed clearly enjoys taking on the Russian at Melbourne Park, having won a five-set epic in 2025.
Tien acknowledged Chang has rapidly improved his game.
‘He’s very encouraging. He’s never getting down whether I’m playing well or whether I’m playing poorly,’ he told reporters earlier in the tournament.
‘He’s always just consistently giving me good energy, a lot of support.’
