Sabalenka served for the contest at 5-3 and came within two points of extending her unbeaten run. But Pegula kept pressing by making her returns and drawing errors off changes in pace to get back on serve.
In the eleventh game, after Sabalenka recovered from 0-40, Pegula broke two points later in an enthralling rally that ended with the three-time champion throwing her racquet after just missing the final shot of the exchange wide.
Pegula then tightened up, missing a pair of match points—the first on a double fault at 40-30. Sabalenka sent the decider into a tiebreak with her own question asking on a crumbling Pegula serve to claim a 16-point game.
The American hit the reset button, striking first for 3-1 by disguising the perfect backhand drop shot the top seed didn’t bother attempting to chase down. A deep forehand on the run caught Sabalenka off guard in earning Pegula a second straight point on return.