Serena Williams will have to beat her sister Venus to win an Open era record 23rd grand slam title after she overcame Mirjana Lucic-Baroni at the Australian Open.
Serena brought an end to Lucic-Baroni’s fairytale run in Melbourne with an emphatic 6-2 6-1 victory, which ensures the most prestigious siblings in tennis will meet for a ninth major final and their first since Wimbledon in 2009.
A win for Serena would see her finally pull clear of Steffi Graf’s Open-era record 22 grand slam titles and move just one short of Margaret Court’s all-time best 24.
Their reunion adds another chapter to a throwback Australian Open, in which Serena and Venus, aged 35 and 36 respectively, will go head to head for the women’s title while Roger Federer, 35, and Rafael Nadal, 30, may yet do battle for the men’s.
Serena will be favourite. She has won seven of her last eight meetings against her older sister and holds a 16-11 advantage overall, since the pair first met professionally in the second round here 19 years ago.
Venus had earlier turned back the clock by beating fellow American Coco Vandeweghe at the Australian Open to reach her first grand slam final in eight years.
Venus last played for a major title at Wimbledon in 2009 and, at 36, she is the oldest entrant in the singles draw at Melbourne.
But the seven-time grand slam champion showed few signs of fading on Rod Laver Arena as she came from behind to beat an in-form Vandeweghe 6-7 (3/7) 6-2 6-3.
Venus lost to Serena in her last run to the final here in 2003 and her progress 14 years later is the longest ever gap between two appearances in the final at the Australian Open.
It gives her the chance to secure an eighth grand slam triumph, nine years after her last at Wimbledon, and add one of the two majors titles she is yet to hold, the other being the French Open.
She is also the oldest woman to make a major final since a 37-year-old Martina Navratilova reached the last hurdle at Wimbledon in 1994.
More than the numbers, however, Venus’ resurgence is even more remarkable given her prolonged struggle with Sjogren’s syndrome - a disorder affecting the immune system - and numerous niggling injuries.
She was forced to withdraw from the first tournament of the year in Auckland earlier this month and arrived with low expectations at Melbourne Park, where she lost in the first round last year to Britain’s Johanna Konta.
When Vandeweghe sent a final forehand long to lose a fourth match point, Venus bounced up and down, and twirled in delight.
“Oh my gosh it means so much,” Venus said.
“Mostly because she played so well, she played so unbelievably well and I had to play defensive all the time.
“There was never a moment of relaxation ever so to get through to the final after a match like this also makes me excited about American tennis as well.”