The tension was clear during — and after — Iga Swiatek and Danielle Collins’ quarterfinal match on the clay courts at Roland Garros.

Swiatek, 23, of Poland advanced to the semifinal round in the Paris Olympics on July 31 after Collins, 30, of the United States retired from the match. The American tennis player later told reporters she was upset with Swiatek’s attitude.

Viewers noticed a terse greeting between the two following Collins’ decision to retire and both players addressed the exchange while speaking to press after the match.

Collins explained, “I told Iga she didn’t have to be insincere about, you know, my injury. There’s a lot that happens on camera, and there are a lot of people with a ton of charisma and come out and are one way on camera and another way in the locker room.”

“And I just haven’t had the best experience, and I don’t really feel like anybody needs to be insincere,” Collins continued. “They can be the way that they are. I can accept that, and I don’t need the fakeness.”

When Swiatek was asked about the exchange with Collins, she told reporters, “I think it’s better to ask her,” and said she’d “rather not get into these because that’s her last year on Tour.”

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At one point during the match, Collins told Swiatek, “There’s like no one behind me. Play at the server’s pace.”

Another tense moment between the tennis players occurred when a strong backhand from Collins flew straight into Swiatek’s body, forcing the Polish athlete to fall to her knees for a moment before recovering. “I couldn’t breathe for some time,” Swiatek told reporters of the hit. “I guess with the adrenaline that you have on court, you don’t feel these kind of things too hard. So I could get back in the game really quickly.”

Collins explained that the injury she suffered was to her abdominal muscle, while also stating that the “conditions here have been brutal” as Paris was hit with a heat wave. “When you have full-body cramps from your toes to your neck and you suffer a heat stroke, it’s very, very difficult to come out here,” she said.

PEOPLE has reached out to a representative for Team USA for comment.

Next, Swiatek will meet Zheng Qinwen from China in the semifinal round to compete for a chance at the gold medal. She’s the first Polish tennis player to reach the semifinals at an Olympic game.

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