NEWPORT BEACH, CA, USA - On a quarterfinal day of topsy-turvy scorelines and wild momentum shifts at the Oracle Challenger Series Newport Beach, No.5 seed Madison Brengle pulled off the most dramatic turnaround, saving a match point en route to ousting No.1 seed Jessica Pegula 1-6, 7-6(7), 6-2 in one hour and 56 minutes.

World No.95 Brengle was initially outmatched in the all-American derby as Auckland runner-up Pegula took control of most rallies with her superior weight of shot - but even in the one-sided opening set, the 29-year-old foreshadowed her dogged refusal to lie down in a titanic five-deuce final game before Pegula sealed the opening act on her third set point. But Brengle had managed to gain momentum with that tussle, and responded by breaking her opponent twice en route to a 5-2 lead in the second set.

Though World No.66 Pegula gathered herself to chip away at this lead to ultimately send the set to a tiebreak, it was Brengle who held firm within it, saving a match point down 6-7 before levelling the match on her third set point. An opening break for Pegula in the decider raised hopes for last year's runner-up - but only briefly, as Brengle wrested the momentum back to break three more times, winning six of the last seven games and the last eight points of the match.

Elsewhere, Nadia Podoroska and No.2 seed Taylor Townsend also bounced back in style from one-sided opening set routs. Argentina's Podoroska has started 2020 on a hot streak, lifting ITF W25 trophies in Malibu and Petit-Bourg, Guadeloupe to start the season, and the 22-year-old remains unbeaten in 14 matches after upsetting No.4 seed Tatjana Maria 2-6, 6-1, 6-1 to reach the biggest semifinal of her career.

Podoroska had been forced to retire due to a wrist injury the last time she faced the German in the second round of Bucharest 2017 - a problem that would sideline her for the following eight months - but today was able to bounce back from an error-strewn first set to dominate the last two. Across the final two sets, Maria would only reach game point twice - winning both games - and Pan American Games gold medallist Podoroska would rattle off 20 of the final 25 points of the match to set up a semifinal against Brengle.

There would be a similar whiplash scoreline for Townsend, who dispatched CoCo Vandeweghe 1-6, 6-1, 6-1 in one hour and 19 minutes in another all-American clash. Former World No.9 Vandeweghe's renowned serve was firing well in the first set, whose scoreline belied the number of tight games in it: the 28-year-old was only landing 53% of her first serves, but winning 94% of those points. Both numbers would fall away dramatically as the accuracy and efficiency of her delivery plummeted: Vandeweghe's first serve percentage dropped to 46% in the second set and 39% in the third, and her winning percentage behind it dropped to 55% and then to 22%.

Townsend will face No.6 seed Stefanie Voegele in the last four after the Swiss player survived yet another wildly oscillating match to upset No.3 seed Christina McHale 6-1, 1-6, 6-4 in two hours and 17 minutes.

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