Last week, we did a story about how the 30s are the new 20s in men’s tennis, with a surprising number of active players over 35 doing really well against younger opponents these days. Historically, this trend has been even more unlikely on the women’s side.

Seven-time Grand Slam champion Justine Henin called it quits for the second and final time at 28. Former world No. 1 Amelie Mauresmo announced her retirement at 30. Martina Hingis, winner of five Majors, retired from the singles competition for the first time at the young age of 23, and then again a few years later. Lindsey Davenport stopped playing competitively in singles events in her early 30s. Even the great Steffi Graf retired at 30, while her rivals Gabriella Sabatini and Arantxa Sanchez-Vicario played their final singles matches at 26 and 31 respectively.

When players like Martina Navratilova or Chris Evert played on into their mid-30s and beyond, fighting gallantly against teen upstarts, fans cheered them on lustily, hoping they would defy the odds. It was special because it was so rare. The grind of the tennis tour took its toll on players’ bodies, and as they slowed down, it was impossible to keep up with younger, fitter, faster players.

This year, at the Australian Open, three of the four semi-finalists on the women’s side are in their mid-30s. Two of them have remarkable stories that would move the most hardened fans. Joining the three veterans is a young American with a bit of an attitude. The question is, can anyone stop Serena Williams from surpassing Steffi Graf’s record to win her 23rd Grand Slam singles title on Saturday?

Mirjana Lucic-Baroni: The fairytale

Mirjana Lucic-Baroni's last Grand Slam semi-final appearance was at Wimbledon in 1999 (Image credit: Reuters)

It was Graf who defeated Mirjana Lucic-Baroni back in the Croatian’s last Grand Slam semi-final appearance, at Wimbledon in 1999. At that time, Lucic-Baroni was 17; she was a teen prodigy. A top junior player, she was only the third player in the Open Era to win two junior Grand Slam singles titles before the age of 14. Hailed as one of the rising stars in the women’s game, Lucic-Baroni won the Australian Open women’s doubles event at 15, and became the youngest player to successfully defend a WTA singles title at 16.

However, the bright tennis future people had envisioned for her was not to be. Mirjana Lucic, as she was then known, suffered personal problems and gradually disappeared from the public eye. Later, she would reveal that she had been abused by her father. She also suffered injuries and financial problems that together kept her out of the game for years.

Between 2004 and 2006 she played only a couple of tournaments, and even though she did return to competitive tennis in 2007, she mostly played the qualifying rounds and challenger events. She didn’t compete in any Slams from 2003 to 2009. It was a long climb back into the top 100. There was a brief flicker in 2014 when she reached the fourth round of the US Open, but no one could have expected her to reach another major semi-final at 34. The now married Lucic-Baroni came into this year’s Australian Open ranked 79.

Hers has been the fairytale of this year’s Aussie Open. She beat third seed Agnieszka Radwanska in the third round and, on Wednesday, took out fifth seed and last year’s US Open runner up Karolina Pliskova in the quarter-final. With the crowd firmly behind her, Lucic-Baroni took two medical timeouts to treat blisters and her heavily strapped leg, before finally prevailing in a hard-fought three-setter. It was an emotional moment. After the match, Lucic-Baroni said, her voice cracking, “This has truly made my life, and everything bad that happened, has made it okay.”

It would be difficult for anyone, player or fan, to begrudge Lucic-Baroni this moment. Even Serena Williams, after her own quarter-final victory over in-form Brit Johanna Konta, acknowledged how special it was to see her back. ‘’No matter what happens,” she pointed out, “someone 34 or older will be in the final.’’

Venus Williams: The resurgence

Venus Williams is yet to drop a set in the 2017 Australian Open (Image credit: Reuters)

What she didn’t say out loud was that she hopes there are two. Her sister Venus, 36, is the oldest Aussie Open semi-finalist (male or female) in the Open Era. The 2003 runner-up at this event, Venus has yet to drop a set en route to the semi-final. The past year has seen a sort of resurgence from Venus, who reached the Wimbledon semi-final last summer.

Her quarter-final victory over Anastasia Pavlyuchenkova may not be quite as unexpected as Lucic-Baroni’s result, but it’s worth noting that Venus was diagnosed with Sjogren’s syndrome in 2011, a chronic autoimmune disease that causes extreme fatigue and joint pain. She has not won a Slam since the French Open in 2010 and saw her ranking drop to 102 at the end of the following year.

Currently ranked 17th in the world, Venus came to Australia with a lingering right arm injury. Now, she is just one match away from a potential final against her sister. As she said, quite firmly, after her match, she’s not done yet. “I want more,” she announced.

Coco Vandeweghe: The kid

Standing in the way of that dream final is compatriot Coco Vandeweghe. At 25, she belongs to a different generation of tennis players compared to the other three semi-finalists. As a kid, she says she once chased after Venus at a tournament in California, trying to get her autograph. She failed to get it. The daughter of an Olympic swimmer, Vandeweghe has made her presence felt this year in Melbourne, beating defending champion and world No. 1 Angelique Kerber and last year’s French Open champion Garbine Muguruza in straight sets on her way to the semi-final.

On court, she is feisty, often yelling at herself. Off court, she appears unusually confident, walking with a swagger and shrugging off the prospect of losing to higher-ranked opponents. Not everyone appreciates the American’s outspoken, no-nonsense style. But she will not care about that as she tries to make it to her first ever Grand Slam final against her childhood idol.

Serena Williams: The favourite

Vandeweghe’s personality, Venus’s revival, and Lucic-Baroni’s incredible journey might all make for fascinating stories. But the title is Serena’s to win or lose. It is only a matter of time before she wins that 23rd Major and with some of her toughest rivals – Muguruza, Kerber, Azarenka – missing now, this might be the easiest route. Standing in her way is a player ranked 79th in the world, who has already fulfilled a lifelong dream by reaching the semis, her older sister whom she has owned in recent years, and a brash young American with far less experience than the others. Serena is primed to win her seventh Australian Open singles title this weekend. But first, let’s enjoy and appreciate the semis on Throwback Thursday, because as Serena said in her on-court interview after beating Konta, “The 30s are the new 10s.”

Oindrila Mukherjee tweets here.