It was far from a full house on Court 17 at the U.S. Open on Saturday but those present are believed to have witnessed a moment of LGBTQ sporting history.

Daria Kasatkina’s third-round tie against Greet Minnen was already known to be pitting the only two out gay players in either of the main singles draws against each other.

However, the contest took on extra significance when the claim was made that this was the first-ever singles match at a Grand Slam between two publicly out gay players.

Expert journalist and author Bastien Fachan posted to social media that this was history in the making at Flushing Meadows, citing a Reddit source and emphasising the word ‘openly’ when responding to replies.

Tennis historians on Twitter / X went to work, with one mentioning that Billie Jean King last faced Martina Navratilova in a Slam singles match at Wimbledon in 1980 — a year before Navratilova came out publicly.

Debate on the validity of the ‘landmark’ is likely to hinge on a definition of what quantifies being ‘publicly out’ in an age before social media.

For example, Navratilova was beaten in the 1993 Wimbledon semifinals by Jana Novotna, whose relationship with coach Hanna Mandlikova was known by many in and around the sport at that time.

Some would argue that the notoriously shy and private Novotna, who sadly passed away in 2017, cannot be said to have been publicly out in the way Kasatkina or Minnen are now.

The perceived openness of other lesbian and gay players during their Grand Slam careers — when compared to a modern-day view of what it means to be publicly out — will also form part of this conversation.

A French Open second-round meeting in 2008 between former world no 1 Amelie Mauresmo, who came out publicly as a teenager nine years previously, and Carla Suarez Navarro was also put forward as a suggestion.

However, the Spaniard was only 19 years old herself when she played Mauresmo at Roland Garros and it is not thought she was publicly out at that time. Earlier this summer, Suarez Navarro and her girlfriend, former Barcelona soccer player Olga Garcia, announced they had welcomed twin daughters.

This mooted milestone is highly unlikely to have been on the minds of Minnen or Kasatkina but with both players having advocated on behalf of fellow LGBTQ people in recent months, they will hopefully appreciate the resonance should they learn of it later on.

Indeed, Minnen quote-tweeted Fachan a couple of hours after her defeat, writing simply, “it was a pleasure” alongside a rainbow emoji.

Greet Minnen matched her best-ever singles run at a Grand Slam by reaching the third round.

Kasatkina, who as a Russian athlete is playing under a neutral flag in New York City, had stuttered her way through her earlier matches this week but looked much more composed against Minnen, winning 6-3, 6-4 to reach the U.S. Open fourth round for the second time in her career.

The 26-year-old hinted recently that she would prefer her name to appear alongside a Pride rainbow flag when competing.

To keep that flag flying beyond the last 16, she will have to get past no 2 seed Aryna Sabalenka. The Belarusian is also down as a neutral.

The tournament’s official website noted Sabalenka holds the edge in their overall head-to-head but added: “In an interesting twist, both of Kasatkina’s wins have come on Sabalenka’s favored surface (hard courts) instead of her own preferred clay.”

There is sure to be a bigger attendance for that encounter than Kasatkina had on Saturday. Around the world, more and more LGBTQ people will be cheering her on too.