This year, Raducanu returned to New York – the scene of her 2021 title success as a teenage qualifier – riding a wave of optimism.
Looking more carefree and content, she has played some of her best tennis since that extraordinary triumph and is close to climbing back into the world’s top 30.
But this defeat provided another reality check.
Leading into the match, Raducanu warned of 2022 Wimbledon champion Rybakina’s ability to take the racquet of an opponent’s hand with her enormous serve and penetrating returns.
That is exactly what happened in a one-sided first set lasting only 27 minutes.
Rybakina’s groundstrokes were clean and crisp off both wings, with a stream of winners painting the baseline and leaving Raducanu looking rather helpless.
A total of 23 winners from 26-year-old Rybakina underlined her dominance from the back of the court.
Raducanu’s serve had been the bedrock of her game in two clinical opening wins against lowly ranked qualifiers Japan’s Ena Shibahara and Indonesia’s Janice Tjen.
But she did not land anywhere near as many first serves on Rybakina, which instantly put her under pressure against an opponent who represented a huge step up in class.
Kazakhstan’s Rybakina, whose power from the baseline is among the very best when she finds her groove, continued to redline in the second set.
It was felt Raducanu stood a chance if she managed to get Rybakina moving around the court, but the pace of her opponent’s ball meant she was not given the time to do so.
Despite winning numerous WTA titles on hard courts, Rybakina had never gone past the third round at Flushing Meadows before.
Next she will face Italian seventh seed Jasmine Paolini or 2023 Wimbledon champion Marketa Vondrousova for a place in the quarter-finals.
