Barty withstood 15 aces from Bertens in the 2-hour, 18-minute match to advance to her second consecutive final in Sydney.
She will play two-time Wimbledon champion Petra Kvitova or Serbian qualifier Aliaksandra Sasnovich in Saturday’s final. Kvitova and Sasnovich were scheduled to play later Friday, although their match was being delayed by rain.
“It’s amazing. It truly has been a phenomenal week of tennis,” Barty said. “I feel like I’ve played great the whole week. I’ve had tough opponents every single round, and I’m really excited to have another shot at the title.”
Italian Andreas Seppi advanced to Saturday’s men’s final by beating Diego Schwartzman 7-6 (3), 6-4. Seppi beat top-seeded Stefanos Tsitsipas in the quarterfinals and will play in his first final since June 2015 in Germany.