NEW YORK -- Coco Gauff and Karolina Muchova remained poised during their US Open semifinal match at Arthur Ashe Stadium on Thursday, even as environmental protesters caused a disruption lasting nearly 50 minutes.

Gauff was leading 6-4, 1-0 when play was stopped. When the match resumed, Gauff held on to defeat Muchova 6-4. 7-5. 

Gauff holds off Muchova to reach US Open final

The USTA issued a statement after the match:

"Following the first game of the second set in the Gauff-Muchova match, play was halted due to a protest conducted by four spectators.

"Three of the four protesters were escorted out of the stadium without further incident. The fourth protester affixed their bare feet to the floor of the seating bowl. Due to the nature of this action, NYPD and medical personnel were needed in order to safely remove this individual from the stadium.

"The four protesters were taken into NYPD custody."

Afterward, Muchova said she didn't notice at first. "I just thought it was fans screaming, cheering," she said.

After dropping the first set, Muchova used the time to try and reset. She admitted to feeling flat for much of the match.

"I could talk to my coaches," Muchova said. "They were trying to wake me up. I think then after the break I actually played a little bit better, but it was not enough to play great against Coco, to beat her."

Gauff was able to shrug off the delay by keeping things light with her team in the gym. 

"I think that throughout history moments like this are definitely defining moments," Gauff said. "I believe in climate change. I think there are things we can do better. I know the tournaments are doing things to do better for the environment. 

"I always speak about preaching about what you feel and what you believe in. It was done in a peaceful way, so I can't get too mad at it. Obviously, I don't want it to happen when I'm winning up 6-4, 1-0, and I wanted the momentum to keep going. But hey, if that's what they felt they needed to do to get their voices heard, I can't really get upset at it.