Venus Williams held up her end of the deal for another all-sisters Australian Open final with a 6-7 (3), 6-2, 6-3 win over CoCo Vandeweghe, becoming the oldest player to reach the final of the tournament in the Open era.
The 36-year-old Williams is back in a Grand Slam final for the first time since Wimbledon in 2009 and her first here since 2003, when she lost to her younger sister, Serena.
She could get a chance to avenge that loss — 22-time major winner Serena Williams defeated 34-year-old Mirjana Lucic-Baroni later Thursday.
"It means so much, mostly because she played so well. I mean, she played so unbelievable," Williams said of the 25-year-old Vandeweghe, who was playing her first major semifinal. "To be able to get through the final from a match like this — I'm excited about American tennis as well."
Williams needed four match points on Vandeweghe's serve in the last game before converting. Then she put both hands on her face, almost in surprise.
"It's more than a cherry on top," she said. "It's more than I dreamed of."
Serena Williams is one win away from a record 23rd Grand Slam title after setting up an all-Williams final at the Australian Open against her older sister, Venus.
No. 2-ranked Serena Williams, a six-time Australian Open winner, overwhelmed Mirjana Lucic-Baroni 6-2, 6-1 in the second women's semifinal on Thursday after Venus Williams beat fellow American CoCo Vandeweghe 6-7 (3), 6-2, 6-3.
Serena broke Lucic-Baroni five times to win the match in 50 minutes.
Earlier, Bob and Mike Bryan earned a shot at a seventh Australian Open doubles title after a rain-interrupted 7-6 (7-1) 6-3 semifinal win Friday over Pablo Carreno Busta and Guillermo Garcia-Lopez.