Pegula took back the momentum by winning the first three games of the second set before Gauff dug in her heels, saving three set points in the 10th game to level it at 5-5
Potapova, who began representing Austria after obtaining citizenship in December, is one of several Russian-born players to have switched allegiance since Russia's 2022 invasion of Ukraine
Sabalenka earlier beat Kasatkina 6-0 7-5 on a sun-drenched Court Suzanne Lenglen for her 100th win as the top-ranked woman, making her only the ninth player to achieve the feat since the inception of the WTA rankings
World number two Rybakina put on a clinical display, never facing a break point on her own serve and landing nine aces while Shnaider could manage only one
Sabalenka took full advantage of a series of errors from Rybakina to win the opening set, and the four-times Grand Slam champion then raced ahead 4-0 in the second