(CNN) -- Michael Chang is in the record books as the youngest winner of a grand slam but his French Open triumph in 1989 is largely remembered for one extraordinary moment in a last 16 match against Ivan Lendl.
Few people gave the 17-year-old Chinese American much chance against the world number one and three-time French Open champion.
The odds lengthened still further when the Czech took a two sets lead.
But Chang fought back to level at two sets all, despite suffering from cramp at the end of the fourth set.
"I actually knew I was in trouble at the end of the fourth because I started cramping. Our match was about four hours and 37 minutes and against Ivan on clay, that's a pretty long time," he told CNN.
But it got even worse as the match went into the decider on Court Philippe Chatrier at Roland Garros as Chang recounts.
"In the fifth set, at 2-1 in the fifth set, I almost decided to call it quits, I couldn't serve, I couldn't dig out any balls that were hit in the corners and I walked to the service line, to basically tell the umpire I can't play anymore, I'm done."
But Chang, who has strong religious beliefs, had a sudden change of heart.
"I get to the service line and I get an unbelievable conviction, just a conviction in my heart and it was almost as if God was saying, what are you doing?
"It dawned on me that if I was to quit then and there, every other difficult time I have there on the court it was just going to make it that much easier to quit.
"And from there, it wasn't so much a matter of winning and losing, my objective that day was to finish the race which was that match, which was that fifth set. Win or lose I had to finish the match."
The resilient Chang started to hit slow looping returns "moonballs" to recover and give himself more time and it worked as he forged a 4-3 lead -- until the cramps returned with a vengeance.
Trailing 15-30 on his own service, the writing was on the wall when Chang decided on an unconventional approach, which was to decide the outcome of the match.
"Then at 15-30, spur of the moment, I was just like, I'm going to throw an underhand serve in here, cause I'm not doing anything off my first serve anyways.
"Let's see if maybe I can scrape a point. I hit the underhand serve, Ivan was kind of surprised about it, moved, kind of got squeezed in because of the spin and had to come in because the serve was so short. I hit a passing shot, clipped the tape and it went off the top of his racket and the crowd went absolutely nuts !.
"And you can see Ivan going back to the baseline to return the 30-all point and he was kind of going like this (tapping his head) and it became a sort of mental battle."
Lendl did not win another game as Chang closed out the match, but it was another unconventional tactic which sealed his victory as he forged two match points on his opponent's service.
"I had two match points so I might as well take a crack at one of them. I've got a second serve coming, he's got to be a little bit tight, my shots have been going in so I might as well take one good rip at it, I've got another one if I happen to miss it and that's what my mentality was."
Chang's "tactic" was to stand right in on Lendl's delivery almost at the service line and it rattled the legendary Czech.
"The crowd started going nuts, they started whistling and stuff like that. He actually looked up at Richard Ins (the chair umpire) and was like hey, the crowd's making a noise, can I hit a first serve, and Richard told him no, and he stepped up and threw the double, double fault."
It was an extraordinary end to an extraordinary match and Chang eventually progressed into the title match against Sweden's Stefan Edberg.
Once again he faced an uphill battle as Edberg recovered from a set down to lead two sets to one and was on top in the fourth.
"The fourth set I should have lost, I was down 11 break points and I only had one break point, it just happened to be on set point," Chang said.
"And I snuck that one, and then I think Stefan was a little tired in the fifth even though he was up early with a break."
Once it was retrieved, Chang charged through the decider, taking it 6-2 to claim his place in the tennis record books
With the momentous events in Tiananmen Square taking place on the middle weekend of that French Open, Chang wanted to dedicate his victory to the wider Chinese community in his native America and around the world.
"I almost kind of feel that it was almost God's purpose for me to win that French Open.
"I really think it was about putting a smile on Chinese people's faces when there wasn't a whole lot to smile about. That's part of the reason why I think the French Open happened in the way that it did."
It's 23 years since Chang's unexpected triumph - his only grand slam title.
He lost to Thomas Muster in the 1995 French Open final and to Boris Becker and Pete Sampras at the Australian and U.S. Open finals of 1996.
The 1995 loss to Austrian legend Muster still hurts, but Chang believes it would have been hard to match the impact of his 1989 triumph.
"I don't know if any grand slam win following that one would have been more special. That being said, I would have liked to have won in 1995 in the finals but it was not meant to be," he said.
Chang remained a major force on the ATP tour throughout the 90s, a decade which began with a notable triumph for the United States.
" I think the other highlights of my career would have to be winning the Davis Cup in 1990 and a career No.2 in the world, being inducted into the International International Tennis Hall of Fame in 2008 and also meeting my wife Amber through tennis! I have much to be thankful for!" he added.
Chang retired from the main tour in 2003, but still competes on the Champions Tour and in World Team Tennis.
He pairs up in mixed doubles with his wife of four years Amber Liu, who is a former two-time NCAA champion from Stanford University.
They have a young daughter, "hopefully there'll be a racket in her hand sometime soon," said Chang, who is a keen supporter of junior tennis.
He also keeps an eye on the achievements of Chinese players and welcomed Li Na's victory in the women's singles at last year's French Open.
"I do know Li Na a little bit, I did send her a congratulatory email."
Chang is also in content with another Chinese American who is making making the sort of headlines he did back in 1989.
Both he and Knicks basketball sensation Jeremy Lin share a strong Christian faith and they have spoken about their wider responsibilities.
"As far as being a role model, I think it's very important for Jeremy to realize that he is just that not only for the Chinese community but also everywhere else.
"To have the opportunity to touch and impact lives is such a honor and privilege and I hope Jeremy will use the platform that he has to inspire and encourage people wherever he goes."
Chang was certainly an inspirational figure during his tennis career and epic triumph at the French Open in 1989 looks set to stay in the record books for many years to come.