The flawless victory for Rybakina, who won Wimbledon in 2022 and this year's Australian Open, booked a last-eight clash with Olympic champion Zheng Qinwen and left the Kazakh one win away from becoming world number one for the first time.
Second seed Rybakina raced through the opening set in 22 minutes, converting two of her three break-point opportunities before sealing it with a booming serve to leave two-times New York champion Osaka on the ropes at Louis Armstrong Stadium.
The 13th-seeded Osaka, who had arrived in style in a fur-collared overcoat that featured oversized signage, a mural-like city scene and a portrait, showed greater resistance early in the second set, but Rybakina soon seized control again.
Osaka clutched her left leg at 2-2 in the second set, still feeling the effects of an Achilles niggle that flared up in the third round, but the 28-year-old managed to save a break point and stay in the fight.
Rybakina continued to heap pressure on Osaka with her deep groundstrokes and earned the decisive break in the seventh game when her Japanese opponent hit a forehand into the net, before she closed out the match in 66 minutes.
