Roland-Garros in Paris CNN  — 

Kei Nishikori wasn’t even born when his coach, Michael Chang produced one of the most remarkable tennis shots of all time.

Struggling against the top-ranked Ivan Lendl in the fourth round of the 1989 French Open, Chang used an underarm serve as he clinched one of the biggest upsets of all time. Just 17 years of age, Chang went on to defeat Sweden’s Stefan Edberg in the final to become the youngest male grand slam winner in the Open era, a record he still holds.

“I have seen this moment many times,” Nishikori told CNN Sport in an interview at Roland-Garros in Paris after beating France’s Jo-Wilfried Tsonga to reach the second round.

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PARIS, FRANCE - JUNE 07:  Novak Djokovic of Serbia serves in the Men's Singles Final against Stanislas Wawrinka of Switzerland on day fifteen of the 2015 French Open at Roland Garros on June 7, 2015 in Paris, France.  (Photo by Julian Finney/Getty Images)
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“The way he fights, it was amazing,” said the 29-year-old Japanese player. “I know he was hurting and cramping, but he kept fighting every point. Also, he had to use his mental strength, too. He changed up something, with the underarm serve, and it worked.”

‘Same style’

Nishikori, who was born seven months after Chang won his lone major championship, added the American to his coaching team, which also includes the Italian Dante Bottini, in December 2013.

Chang’s input had an immediate impact, with Nishikori becoming the first man from Asia to reach a Grand Slam singles final at the 2014 US Open, where he lost to Croatia’s Marin Cilic.

Nishikori with his coach Chang in 2014.

Although the seventh-seeded Nishikori wasn’t sure if he would ever use an underarm serve, he said the now 47-year-old Chang has “always” been an inspiration to him.

“We play the same style of game, and he is a great coach for me, and I am so happy to have him on my team. He always gives me good motivation, and he sees something very quickly,” said Nishikori, whose double-handed backhand was once lauded by Roger Federer as “one of the best in the game.”

READ: Michael Chang on his cheeky shot

Sony backing

Financially supported by a Sony executive, Nishikori left Japan at the age of 13 to hone his tennis skills in the US.

The bet paid off as he became the youngest man ranked inside the top 100 of the men’s ATP Tour just five years later. A former world No. 4, Nishikori is so famous in Japan, he is barely able to walk the streets without getting mobbed.

His fame has turned Nishikori into one of the richest players in tennis, striking deals with a host of blue-chip companies, and out-earning even the likes of 15-time major winner Novak Djokvovic of Serbia in terms of sponsorships, according to Bloomberg News.

Nishikori serves as Chang looks on during a practice session in Melbourne, Australia in January.

Japanese zen

In Paris, about 40 Japanese journalists attended his press conference, while he was interviewed by former Japanese tennis star Kimiko Date immediately after.

Surrounded by bodyguards while walking to the studios of TV Tokyo, Nishikori appeared completely unfazed by fans shouting his name and asking for autographs as he conducted the interview.

His calmness is a trait he shares with his fellow Japanese tennis superstar, Naomi Osaka.

Nishikori, who knows the US Open and Australian Open winner well, said he has been impressed by her meteoric rise to the top of the rankings.

“It’s amazing, winning two grand slams, very quick, and she hadn’t won many tournaments before that,” said Nishikori. “Crazy mental strength she has.”

Osaka in action earlier in the week in Paris.

READ: Osaka can win 10 slams, says Li

Away from the court, Osaka is “very funny,” Nishikori said. “She always jokes around with me. it’s great to have Naomi for Japanese tennis.”

The two tennis stars do not commiserate on the burdens of Japanese fame, however. “It doesn’t change much,” Nishikori explained. “I focus on myself, and I don’t try to see other stuff outside of the court.”

Nishikori has had a solid clay-court season so far, reaching the semifinals in Barcelona and the quarterfinals in Rome. His best outings in Paris include quarterfinal appearances in 2015, when he lost to Tsonga, and in 2017, when he was beaten by Andy Murray.

Can he make his coach proud and win the title on Chang’s 30th Parisian anniversary?

“I don’t know,” Nishikori said, with usual understatement. “I will try.”