Anastasia Pavlyuchenkova was forced to rally from an early deficit in order to secure her spot in Saturday’s Citi Open women’s final. She might not be fully certain how she did it.

A native of southeastern Russia, Pavlyuchenkova said Friday’s humidity at the William H.G. Fitzgerald Tennis Center in Rock Creek Park nearly caused her to pass out during her 4-6, 7-5, 6-4 semifinal victory over American Vania King.

She’ll meet unseeded Magdalena Rybarikova, who upset third-seeded Sloane Stephens, 6-3, 6-3.

Pavlyuchenkova’s problems with the humidity began in warmups. During the week, She said she had been able to deal with the heat. She drank plenty of fluids and changed her clothes throughout the day.

“It just hit me,” Pavlyuchenkova said. “Those things you can’t control.”

After dropping the first set, Pavlyuchenkova had trouble breathing and requested to see the tournament’s doctor. During the 10-minute break, Pavlyuchenkova attempted to battle the exhaustion by covering herself with wet towels and bags of ice.

“I don’t know, seriously, how people live here,” said Pavlyuchenkova, who is the tournament’s top seed. “It’s unbelievable. I think they should consider changing the date for the tournament or play the match in the night session.”

Although the break helped, Pavlyuchenkova said her consciousness never fully returned. Nevertheless, she bounced back and won the final two sets. Her body forced her to play quickly, as she thought she may wilt during a long rally.

The style caused many unforced errors, but Pavlyuchenkova was able to land five aces in the final two sets and break King’s serve five times.

“Everyone can win matches and can feel good,” Pavlyuchenkova said. “That’s the point of not feeling great, not playing your best tennis and still trying to find a way to win.”

In men’s singles, James Blake’s impressive unseeded run came to a halt as he fell to Alexandr Dolgopolov, 7-6 (7-3), 6-4. Dolgopolov masterfully controlled the lines throughout the match. Blake double-faulted to end the match.

The tournament’s second seed, Dolgopolov will meet No. 8 Sam Querrey in the semifinals. Querrey was a 6-4, 6-4 winner over Kevin Anderson.

Tommy Haas and Mardy Fish advanced easily and will meet in the semifinals.

Haas, the fourth seed, topped fellow German Kamke, 6-1, 6-2, and top-seeded Fish was a 6-3, 6-4 winner over Xavier Malisse. Fish and Haas live near each other in California and often train together.

“You have to put it in perspective and say this is the guy that is trying to take my lunch tomorrow,” Fish said.

Fish said he, too, had trouble with the heat and resorted to a strong mental approach.

“A lot of it is just convincing yourself that you’re going to last longer than the other guy,” Fish said. “And convince yourself that you’re going to win.”