Osaka, 27, gave birth to her daughter Shay in July 2023 and returned to the WTA tournament six months later.
The four-time Grand Slam winner lost in the first round of her return to the Grand Slam at last year’s Australian Open, before being eliminated in the second round at Roland Garros, Wimbledon and Flushing Meadows.
But the former world number one will get off to a great start in 2025, beating Frenchwoman Caroline Garcia in three sets in her opening match before defeating 20th seed Muchova in less than two hours.
“Honestly, it took everything,” Osaka said of her comeback victory on Wednesday.
“I felt like I left everything I had on the court. Just to be back on these courts…it really makes my whole year.”
Osaka will play Belinda Bencic in the next round, as the Canadian will play herself for the first time in a Grand Slam since giving birth to her daughter Bella in April 2024.
A third straight win would send Osaka into the fourth round at a Grand Slam for the first time since winning the Australian Open in 2021.
