Naomi Osaka was bundled out of the first round at Indian Wells on Wednesday, falling 6-4, 6-4 to Camila Osorio in the Japanese star's first tournament since injury forced her out of the Australian Open.
Former world No 1 Osaka, now ranked 56th in the world, looked rusty against the 52nd-ranked Colombian, struggling to find the range on her powerful groundstrokes on a chilly night in the California desert.
"There were certain things that felt extremely off because I could only start to practice serving after a certain amount of time and stuff like that," said Osaka. "So I think given the situation, it wasn't that terrible.
"I don't feel like I played well at all, but I had chances to be in the match."
Osorio, making a return from a lengthy injury break herself, challenged Osaka with an array of drop shots and slices and gained the lone break of the opening set for a 5-4 lead.
She served it out without a hitch then broke Osaka to open the second.
The Japanese star immediately broke back, but Osorio gained the upper hand with a break in the seventh game. After Osaka fought off a match point against her own serve Osorio served it out, fighting off four break points to seal it with a stinging forehand winner.
"It's crazy for me, a dream come true," said Osorio, who pulled out of last week's event in Merida, Mexico, with an abdominal injury.
She had never won a match at Indian Wells, and became the first Colombian woman to beat a former world No 1.
Osaka, who returned from a 15-month break last year after giving birth to daughter Shai in 2023, reached her first final since 2022 in Auckland, but retired from the title match with an abdominal injury.
Back for the Australian Open, she was forced to retire from her third round match with an abdominal strain.
"It just feels like a little bump in the road," Osaka said. "I'll be back in Miami and hopefully I'll have way more serve practice under my belt and things like that."
Two-time Wimbledon champion Petra Kvitova, on the comeback trail seven months after giving birth to her son Petr, also fell in the first round.
France's 70th-ranked Varvara Gracheva beat the Czech 4-6, 6-3, 6-4, but the 24-year-old was full of admiration for her 34-year-old opponent, who lifted the trophy at Wimbledon in 2011 and 2014.
"If you let me step back a little bit, I really want to congratulate her," Gracheva said. "Because she had a child quite recently, and I'm so happy that she now has the role of a mother and a tennis player, which is very demanding. It's very inspiring for sports, athletes, women – it's just amazing."
All 32 men's and women's seeds have first round byes in this combined ATP Masters and WTA 1000 tournament.
Gracheva lined up a second-round meeting with ninth-seeded Mirra Andreeva, the 17-year-old Russian who became the youngest ever WTA 1000 champion in Dubai last month.
In other matches, French veteran Caroline Garcia beat US wild card Bernarda Pera 6-3, 6-4 to line up a second-round meeting with second-seeded defending champion Iga Swiatek.