In a competitive, high-quality match, Sabalenga ended Pegula’s early resistance with a fourth break for a 4-2 lead in the first set.
The Belarusian then overcame the disappointment of being broken after missing an early set point by finally taking his fifth chance to close out the set against his opponent in 45 minutes.
But Pegula, knowing victory by any outcome will send him to the semi-finals, is in charge of the second set, facing two break points against him for a 3-1 lead.
After Sabalenta made another break on a double fault – losing a third service in five – Pegula came back from two break points.
An undaunted Sabalenka was punished for missing her first opportunity in the final set of the fourth period to break even, but the four-hour major prevailed ahead,
That proved crucial as Sabalenka embarked on a four-game sweep and, unlike the Wuhan open in October, Pegula was not allowed to drop a late fightback – a forehand victory sealing the winner.
Sabalenka’s coach, Anton Dubrov, left his chair midway through the game after his player became “very distressed”.
“Maybe he made the right move because he was really angry with me and that’s why I was able to get out of the others because I was promoted.”