In November 1997, former world No. 1 Monica Seles met a 16-year-old in a Women's Tennis Association (WTA) tournament in Chicago and lost to the teenager in the quarter-finals.
When Seles attends next month's BNP Paribas WTA Finals Singapore presented by SC Global as the tournament's ambassador, she will be reunited with that opponent, a certain Serena Williams, who is still a dominant force in the game and who only relinquished her No. 1 ranking two weeks ago, after 186 weeks at the top.
Such is Williams' longevity that previous challengers like Justine Henin, Lindsay Davenport and Martina Hingis have come and gone. Now, Garbine Muguruza and Angelique Kerber are finding ways to beat her in Grand Slam finals and the German has already replaced Williams as world No. 1.
Recalling her first professional match against the American, Seles, 42, said yesterday: "I remember after that match, I felt like I had played the future world No. 1.
"But I didn't know Serena would still be playing at 34 at this level. As a former player, I'm just so impressed and in awe of her. There's only one Serena.
I remember after that match, I felt like I had played the future world No. 1. But I didn't know Serena would still be playing at 34 at this level.
MONICA SELES, former world No. 1 women's tennis player, on playing Serena Williams (above) for the first time, in 1997.
"Her career's truly been amazing and she's been able to last at the top alongside the likes of Davenport, Hingis, Azarenka and her sister Venus. She did it with multiple generations."
Seles, speaking to the media via a conference call yesterday, is a nine-time Grand Slam winner who retired eight years ago.
The American also compared her era of women's tennis - where she dominated alongside rival Steffi Graf - to the current game and is proud of how far it has come.
Seles said: "It's a lot better now that the Grand Slams (are not being dominated by just one or two players). Women's tennis has grown so much.
"You look at Kerber's rise to the top and also Muguruza winning the French Open, which was very unexpected.
"There's a lot of up and coming players who put in hard work and perserverance.
WTA Finals Singapore ticket details
Single session tickets are available from $16.90, while the All Singles Evening Pass - allowing you to catch all eight qualified players across a pair of matches - are available from $59.20.
Family Day Packages and Season Passes are also on sale.
For more information, visit www.wtafinals.com/tickets/tickets-hospitality
"That just shows the depth we have in women's tennis right now and they're all making Serena's quest to pass the Grand Slam championships record harder."
A three-time winner of the year-end WTA Finals, Seles said: "I'm very excited to be coming back to Singapore and being there for the championship to see the best ladies in the world compete.
"The last time I was there was in 1990 when I played Jennifer Capriati in a one-night exhibition match. I never really got the chance to see much.
"There are no easy matches and every one is like a Grand Slam final. I'm really honoured to come here as an ambassador to watch the action and see the tennis fans here."