The United States are guaranteed to have a semi-finalist at the Australian Open after Jessica Pegula continued her dream run to set up a last-eight clash with Jennifer Brady on Monday.
World No 61 Pegula claimed a 6-4, 3-6, 6-3 win over fifth seed Elina Svitolina inside the Rod Laver Arena to book a meeting with compatriot Jennifer Brady, who beat Croatia's Donna Vekic in straight sets.
Pegula struggled badly in the second set but regrouped in the decider, breaking former Wimbledon and US Open semi-finalist Svitolina in the fourth game before locking down her first win over a top 10 opponent.
Matching Svitolina's power off the baseline, Pegula rushed the net to knock her opponent off her stride and sealed the win on the first match point when the Ukrainian netted a return.
Pegula, who considered giving up tennis after being sidelined for long spells due to knee and hip injuries earlier in her career, will play her good friend Brady for a place in the semis after the 25-year-old beat Vekic 6-1 7-5.
"Jen is an awesome person," Pegula told a news conference. "She was texting me, 'I'm so happy, I'm so proud. This is awesome'.
"We've all been pushing each other. Why not push each other into a quarter-final, then one of us be in the semis?"
Vekic was hampered by an injury to her right leg and took a medical timeout at the start of the second set after being blitzed by Brady in the opener.
She emerged with fresh strapping above and below her knee and though she managed to take the fight to Brady in the second set the Croatian was barely moving in the final two games.
With the score tied at 5-5 Vekic surrendered her serve to love, a double fault handing Brady the chance to serve for the match.
The American made no mistake, sealing victory when her opponent fluffed a forehand.
