WASHINGTON (AP) -- No. 3 Sloane Stephens survived a three-set fight in her opening match. Fellow American Brian Baker didn't.
Stephens defeated Sesil Karatantcheva 6-3, 2-6, 6-1, but No. 2 Chanelle Scheepers and fifth-seeded Barbora Zahlavova Strycova both lost first-round matches at the Citi Open on Monday.
Baker, a surprise participant in the round of 16 at Wimbledon earlier this summer, couldn't capitalize on a good start in losing 4-6, 6-3, 6-4 to Florent Serra.
Scheepers, ranked No. 42 in the world, fell 6-2, 6-1 to Magdalena Rybarikova. Zahlavova Strycova was beaten by Edina Gallovits-Hall, 7-5, 4-6, 6-3.
Stephens lost the final three games of the second set, including two on her own serve, but opened the third by breaking Karatantcheva twice for a 3-0 lead. The 19-year-old American tacked on two more breaks to advance.
"It was just a matter of a couple of loose points and some weird calls and things that happened," Stephens said of the rough middle set. "I was just a little more consistent in the end and I think that's what carried me through."
Stephens reached the fourth round at the French Open and the third at Wimbledon this year. The Floridian narrowly missed a berth on the U.S. Olympic team, and since Wimbledon she has made first-round exits at her last two tournaments. There was no denying that avoiding an unwanted hat trick crossed her mind.
"You just can't ever lose three in a row, that's all," Stephens said. "That's not even an option."
No. 7 seed Coco Vandeweghe avoided an upset by defeating Olga Govortsova 6-4, 6-1. Eighth-seeded Olga Govortsova topped Karolina Pliskova 6-2, 6-2 to advance to the second round.
Russian Anastasia Pavlyuchenkova is the top seed in the women's draw.
The Washington tournament, a staple on the ATP schedule, is combining with the WTA Tour for the first time.
Mardy Fish, the top-seeded men's player, is scheduled to play his opening match on Tuesday. Fish, the No. 13 ranked player, skipped the Olympics after missing several weeks on tour earlier this year following a procedure to correct a heart problem.
Playing his first full season on tour season since 2005 after missing time with an assortment of injuries and surgeries to various body parts, the 27-year-old Baker started the year ranked No. 456. His stunning result at Wimbledon combined with solid performances on clay courts helped propel the former juniors star and injury-plagued American into the top 100 this month. Since then, he has had three straight opening-round losses, all on hard courts.
"Fitness wise I was fine today. It was not an issue," said Baker, who has already earned a place in the upcoming U.S. Open. "I definitely took some time off after Wimbledon, had some aches and pains. It hasn't been the physical aspect of it. It's just been maybe more the mental aspect, coming back from such a high."
Baker broke Serra's serve twice in the opening set to take a commanding 5-2 lead, but lost his own serve at 3-4 in the second en route to losing that set. In the third, Serra needed just five points on Baker's serve for a 1-0 lead, broke again to make it 4-1 and won as Baker's final backhand sailed wide.
"All summer I played pretty clean matches and was still able to be aggressive when I should have," Baker said. "Today was definitely not my day."
Scheepers committed five double-faults and won only 48 percent of the points on her first serve. That paled in comparison to Rybarikova, the 102nd ranked player this week.
Rybarikova won 20 of 23 points on her first serve, had the only five aces in the match, and jumped out to a 5-0 second-set lead.
Leonardo Mayer beat Guillermo Garcia-Lopez 7-6 (5), 7-6 (8) in the opening match of the men's draw.