Jessica Pegula said she will have to "crack the code" of Elena Rybakina in the Australian Open semi-finals after dismantling error-strewn Amanda Anisimova on Wednesday in an all-American showdown.
The sixth seed won 6-2, 7-6 (7/1) to end fourth-seeded Anisimova's hopes of a third Grand Slam final in a row.
Anisimova racked up 44 unforced errors to Pegula's 21.
Pegula is yet to drop a set in Melbourne and is arrowing in on her first major crown at the age of 31.
The closest she has come was losing the 2024 US Open final to Aryna Sabalenka.
The other semi-final at Melbourne Park is between world number one Sabalenka and Ukrainian 12th seed Elina Svitolina.
"It's awesome," Pegula said of reaching her first Australian semi-final, having beaten defending champion Madison Keys in the previous round.
"I thought it's got to be coming (a semi-final), I feel like I play really good tennis here, I like the conditions here.
"I've been waiting for the time when I can break through."
Next up is Kazakh fifth seed Rybakina, who defeated second seed Iga Swiatek in their quarter-final.
Pegula and Rybakina have faced off six times previously, with their head-to-record split at 3-3.
"She's really tough to play, she has a massive serve, big groundstrokes, cool as a cucumber, you get nothing out of her," said Pegula.
"She's been playing some great tennis since the end of last year but I'm going to do my best to hopefully crack the code on her."
- Head in hands -
Pegula and Anisimova had met three times previously, with the more experienced player winning all of them.
Pegula made a scintillating start at Rod Laver Arena, breaking Anisimova's serve to love and surging into a 40-0 lead on her own serve.
Anisimova belatedly won her first point of the match but Pegula comfortably held for 2-0, then had her flustered opponent under pressure once more.
Anisimova, who enjoyed a breakout 2025 to emerge as a major force in women's tennis, defiantly held serve.
The reprieve was short-lived, Pegula reeling off the next three games for a 5-1 lead inside 20 minutes.
Anisimova, beaten in last year's Wimbledon and US Open finals, showed the first signs of frustration as she whacked the soles of her trainers with her racquet.
Pegula's serve was proving a major weapon and she nailed the first set in 30 minutes as she fired down her sixth ace.
The dueling Americans went with serve in the second set but the 24-year-old Anisimova cut an increasingly frustrated figure as her unforced error count mounted.
Anisimova had her head in her hands as the quarter-final threatened to get away from her.
She reset to break Pegula's hitherto dominant serve, but was broken back straight away with her fourth double fault of the contest.
Three more double faults quickly followed and they exchanged breaks to go into a tiebreak, where Pegula raced away and Anisimova's temper boiled over.
