Serena Williams defeated Simona Halep in the Australian Open on Tuesday, helping her to advance to the semifinals with Naomi Osaka on Thursday.
At Williams' match, her husband, Alexis Ohanian, wore a statement T-shirt, which he selected after asking his followers to pick their favorite option, to show his support.
MORE: Serena Williams shines at Australian Open in stylish one-legged catsuitThe shirt he landed on featured a photo of Williams with the words "GREATEST FEMALE ATHLETE" featured prominently.
The word "female" is crossed out to reflect the widely held belief that Serena Williams is simply the greatest athlete of all time.
Alongside a photo of himself wearing the shirt, Ohanian wrote, "Onward. đź‘Ź Thanks for helping pick my shirt, IG squad. If you want your own, ask @nike."
The gesture in support of Williams comes after the debate on the greatest of athlete of all time was recently reignited online after Tampa Bay Buccaneers quarterback Tom Brady took home his seventh Super Bowl win earlier this month.
Many were quick to call the NFL legend the "G.O.A.T." or "Greatest Of All Time" after the win, but others were quick to point out that Williams has 23 Grand Slam singles titles.
Ohanian, who is always outspoken when it comes to praising his wife, made his stance clear on the greatest athlete debate with his T-shirt.
Williams also shared a post after her win on Tuesday, in which she wrote, "The smile says it all. This proud mama marches on."
In a post-game interview, she described her win as "the best match" she played during the tournament.
The tennis star is currently vying for her 24th Grand Slam singles title, which would tie her with the current record-holder, Margaret Court. She will face off against Osaka on Thursday, in what will be their fourth matchup.