Rybakina, a two-time Grand Slam winner, arrived at Flushing Meadows with question marks around her fitness after retiring injured against Iga Swiatek in Cincinnati.
Though she looked comfortable on court, her movement went largely untested by Frodin – who acted as Serena Williams’ body double in the Oscar-nominated film ‘King Richard’ – as she blew the world number 585 away on serve and dictated points from the baseline.
“We didn’t know if [I was] going to be able to play here or not. I’m pretty happy that I’m playing right now, and we are taking [it] day by day,” Rybakina said about her injury.
“I was not playing for the full week [before the tournament], so seven days no tennis and basically not too much gym I could do movement-wise.
“So it’s a great result after 10 days from that kind of injury.”
After opening the rain-delayed match with a double fault, Rybakina proved relentless on serve, dropping just three points and reeling off three consecutive love holds in the first set.
She didn’t face a break point until the sixth game of the second set, saving both.
Equally clinical in Frodin’s service games, she converted her first three break points to race into a set and 5-1 lead.
However, the young wildcard, making her WTA Tour main-draw debut after winning the United States Tennis Association (USTA) Girls’ 18s National Championship, made Rybakina work to get over the line, saving three match points with aces in her final service game among 11 across the match.
Rybakina served out the win with an ace of her own – her sixth of the match and a tour-leading 363rd of the season.
“She played really well today. She has great shots, great serve, it was no easy,” Rybakina said of the largely unknown Frodin.