Two-time Grand Slam winner Garbiñe Muguruza was not happy with opponent Barbora Krejčíková after the Czech won their fourth-round encounter at the US Open.
The world number nine won 6-3 7-6 but Muguruza was angered by the behaviour of the French Open champion.
Krejčíková took a medical timeout when 6-5 down in the second set in order to receive treatment for a problem with her diaphragm. Following this, the 25-year-old won seven points in a row and subsequently went on to clinch the second set and the match.
After the contest, the pair exchanged a cold handshake at the net with the Spaniard calling Krejčíková “so unprofessional.”
The former world number one was later asked about the incident but admitted she didn’t want to dwell on the matter.
"Listen, I don't really want to talk about this," she said. "I'll let you guys judge what you think about this.
“Well, I think, between players, you know a little bit how to behave in certain moments.”
In response, Krejčíková stressed that she was in need of assistance and was still in some discomfort now.
"At the end I was really struggling and I feel really bad right now. I don't really know what happened but I couldn't breathe. I started to feel dizzy and the whole world was shaking.
"It has never happened to me before. I just gave my all at the end. It's tough because it was my first time on such a big court playing the night session and I was really having fun until then."
This is not the first incident of supposed foul play that has occurred in this tournament. Last week Andy Murray accused third seed Stefanos Tsitsipas of deliberately time-wasting during a bathroom break.
The Brit would go on to lose the match in five sets and later posted a sarcastic tweet which read: “Fact of the day. It takes Stefanos Tsitipas twice as long to go the bathroom as it takes Jeff Bazos to fly into space. Interesting.”
Similarly to Tsitsipas, Krejčíková did not technically break any rules and it is unlikely anything will come of the incident between her and Muguruza. For now, the Czech’s focus is on her quarter-final tomorrow against Aryna Sabalenka, with a spot in the final four at stake.