Venus Williams is back in a Grand Slam singles final for the first time since 2009, and as fate would have it, she’ll be facing her own younger sister, Serena. The decorated pair, who have 29 major singles titles between them, will square off for the Australian Open title Saturday, but Venus Williams has already authored a remarkable story just by getting this far.

At 36, the 13th-seeded Williams had become the oldest woman to reach the Australian Open semifinals. Once there, she dispatched unseeded American CoCo Vandeweghe, 6-7 (7-3), 6-2, 6-3, to reach the final in Melbourne for the first time since 2003.

In the second of Thursday’s semifinals, second-seeded Serena Williams made short work of unseeded Croatian Mirjana Lucic-Baroni, 6-2, 6-1, ending that match in under an hour. Serena Williams defeated her older sister for that 2003 Aussie Open title, one of her six triumphs at that tournament, and she will be seeking her 23rd Grand Slam singles championship, one less than Margaret Court’s all-time record.

“Oh my gosh, it means so much, mostly because she played so well,” an ecstatic Venus Williams said of her victory over Vandeweghe, 25, in an on-court interview after their match. “There was never a moment of relaxation, ever, so to be able to get to the final through a match like this, I’m just, I’m excited about American tennis, as well.”

“Everyone has their moment in the sun, maybe mine has gone on a while, but I’d like to keep that going. I’ve got nothing else to do, so let’s keep it going,” Williams added with a laugh.

Playing in her record 73rd Grand Slam event, Williams will try to win her first major title since Wimbledon in 2008, when she defeated her sister in the final. Serena Williams avenged that defeat at the following Wimbledon, Venus’s final appearance in a Grand Slam singles final before Saturday.

The sisters will play each other in a Grand Slam for the 15th time and the ninth in a major final. Serena Williams holds a 6-2 edge in those finals, with her other loss to Venus coming at the 2001 U.S. Open. In all matches between the two, Serena holds a 16-11 advantage and has won the past seven of eight, with Venus’s most recent such win coming in 2014 at Montreal.

“She’s my toughest opponent — nobody has ever beaten me as much as Venus has,” Serena Williams said. “No matter what happens, we’ve won. A Williams is going to win this tournament.”

Venus Williams has seven Grand Slam singles titles overall, all at Wimbledon or the U.S. Open, so she will be seeking her first Australian Open championship. She’s the oldest woman in a Grand Slam final since Martina Navratilova (37, the oldest in the Open era) at Wimbledon in 1994, but Serena Williams is not much younger at 35.

Vandeweghe was playing in her first Grand Slam semifinal. The niece of NBA executive and former player Kiki Vandeweghe, she had knocked out No. 1 seed Angelique Kerber and No. 7 Garbine Muguruza in the previous two rounds. The three Americans made for the first time a trio of players from the same country had played in a women’s Grand Slam semifinals since Lindsay Davenport joined the Williams sisters at the 2002 U.S. Open.

“Honestly, she’s an inspiration, and she really deserves all the credit today,” Serena Williams said of her sister after her win over Lucic-Baroni, 34. “I am so honored to play her, and she really played so hard, and to get this far, after everything that she’s gone through, she inspires me. So I just really want to give her such a congratulations. …

“For us both to be in the final is the biggest dream come true for us.”