Jessica Pegula has criticised Madrid Open organisers after she and her fellow doubles finalists were not allowed to make presentation speeches.
Victoria Azarenka and Beatriz Haddad Maia beat Americans Pegula and Coco Gauff 6-1 6-4 on Sunday.
All finalists in the singles and the men's doubles addressed the crowd after their matches.
"I don't know what century everyone was living in when they made that decision," said 29-year-old Pegula.
"Or how they had a conversation and decided, 'Wow, this is a great decision and there's going to be no-backlash against this'.
"I've never heard in my life we wouldn't be able to speak. It was really disappointing. In a $10,000 final you would speak.
"It spoke for itself. We were upset when it happened and told during the trophy ceremony we weren't able to speak. It kind of proved a point."
Belarus' Azarenka said it was "hard to explain" to her young son Leo why she was not able to address him in a victory speech.
Gauff wrote: "Twitter format doesn't allow me to say everything I would've said during the speech if we had one."
Tunisia's world number seven Ons Jabeur, who did not play in the tournament, said it was "sad and unacceptable" the players were not allowed to speak.
Asked by BBC Sport for an explanation, Madrid Open organisers said: "The tournament will not comment on the matter."
The Madrid Open offers equal prize money across ATP and WTA events, with singles champions winning just over £1m and doubles champions sharing £330,000.
Pegula, who is ranked third in the world in singles, shared £176,000 with Gauff as runners-up.
Why Madrid Open faces 'sexist' backlash
The incident brought more accusations of sexism at the clay-court tournament, one of the most prestigious outside the four Grand Slams.
Ball girls for the men's matches wore different outfits for Sunday's final between Carlos Alcaraz and Jan-Lennard Struff after complaints about the crop tops and short skirts they had worn during the rest of the tournament.
The ball boys for the women's matches wore baggier polo shirts and longer shorts than the ball girls.
Another incident cited as an example of how women's players were treated differently to men centred around birthday cakes.
Spain's world number two Alcaraz was presented with a three-tier cake for his 20th birthday after winning his semi-final on centre court on Friday.
Belarus' world number two Sabalenka, who won the title on Saturday, received a more modest cake when she turned 25 on Friday, when she did not have a match.
In response to a tweet from a fan describing the difference in cakes as "astounding" and "misogyny", two-time major champion Azarenka said on Friday: "Couldn't be more accurate on the treatment."
Madrid Open tournament director Feliciano Lopez said he was "surprised" by her reaction and defended the decision.
He was stood behind Azarenka and the other women's finalists on Sunday when they were told there would be no speeches.
Pegula, who is a member of the WTA Players' Council, said: "There had been a lot of drama in Madrid this year, on a variety of different things. There was a lot of tension and it got worse. That didn't help the situation."
On the wider issues at the Madrid tournament, she said: "Out of all the drama the end goal is to figure out solutions. This cannot happen again - it needs to be changed."
The Women's Tennis Association (WTA), the governing body of the women's tour, has not commented.