MELBOURNE, Australia (AP) — Serena Williams is one win away from a record 23rd Grand Slam title after setting up an all-Williams final at the Australian Open. Now the only person standing in her way is her older sister, Venus.

No. 2-ranked Serena Williams, a six-time Australian Open winner, overwhelmed Mirjana Lucic-Baroni 6-2, 6-1 in just 50 minutes in the second of women's semifinals on Thursday after Venus Williams beat fellow American CoCo Vandeweghe 6-7 (3), 6-2, 6-3.

"She's my toughest opponent — nobody has ever beaten me as much as Venus has," Serena Williams said. "I just feel like no matter what happens, we've won.

"She's been through a lot, I've been through a lot. To see her do so well it's great. I look forward to it — a Williams is going to win this tournament."

The 36-year-old Venus Williams is back in a Grand Slam final for the first time since Wimbledon in 2009 and her first in Australia since 2003, when she lost the only previous all-Williams final at Melbourne Park and described it as a "battle royale."

She tossed her racket after clinching the 2-hour, 26-minute semifinal on her fourth match point and put her hands up to her face, almost in disbelief, before crossing her arms over her heart. She then did a stylish pirouette on the court, smiling broadly, as the crowd gave her a standing ovation.

Venus Williams has overcome an energy-sapping illness and is playing her best tennis since being diagnosed with Sjogren's syndrome in 2011.

"Everyone has their moment in the sun," she said. "Maybe mine has gone on a while. I'd like to keep that going. I've got nothing else to do so let's keep it going."

Serena Williams' celebration was more subdued after her lopsided win over 34-year-old Lucic-Baroni, who was playing her first semifinal at a major since Wimbledon in 1999. Of all the comeback stories in the tournament — and there's plenty, including Roger Federer's return from six months on the sidelines to set up a semifinal against Stan Wawrinka — Lucic-Baroni's return to the top level after so much time struggling out of the game has captured the most heartfelt attention.

Even Serena Williams, who last played the Croatian in 1998, said Lucic-Baroni was an inspiration.

Lucic-Baroni took a selfie with her cell phone on the court before waving and leaving Rod Laver Arena.

Serena didn't get to watch much of her sister's match, but she knew the result before she went out to play.

"Obviously I was really proud of Venus — a total inspiration, my big sister," Serena said. "She's basically my world and my life. She means everything to me. I was so happy for her. For us both to be in the final is the biggest dream come true for us."

Venus Williams has won seven major titles, but none since Wimbledon in 2008. Her gap between major finals is the longest for any player in the Open era. She's also lost six of the eight Grand Slam finals she's played against her younger sister, and is 11-16 in their career meeting at tour-level.

Asked what it will take to win the final, Venus Williams said: "Honestly, I probably just need to continue playing like I'm playing. I haven't played badly.

"I lost a set today. I was not happy about it. But my opponent deserved that set. So what else could I do? Try to get the next two."

Against her sister, she said, "I will try to do the same."

Venus Williams is the oldest player to reach a women's major final since Martina Navratilova, then 37 and 258 days, at Wimbledon in 1994.

The 25-year-old Vandeweghe was playing in the last four at a major for the first time and was the only semifinalist younger than 34. She'd advanced with back-to-back wins over top-ranked Angelique Kerber and French Open champion Garbine Muguruza and took charge against Venus Williams in the first-set tiebreaker.

But Venus Williams rallied after dropping a set for the first time in the tournament, breaking Vandeweghe four times over the final two sets and putting pressure back on her fellow American.

Vandeweghe said earlier in the tournament she'd admired the Williams sisters as an up-and-coming player, and once asked for Venus' autograph. Venus Williams said one of the best things about her longevity in the game was having an influence on other players.

"Growing up, all I wanted was to have an opportunity to play these tournaments. But then you get here and then you have an opportunity to inspire other people," she said. "It's more than a cherry on top. It's more than I dreamed of."

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.