Are we heading for another all-Williams Australian Open final?

For a while, it was merely inevitable that Venus and Serena would contest the final of tennis’ four Slams, but time waits for nobody and now the Williams sisters are very much grandee veterans of the court.

Over the past week and a half however, tennis’ greatest siblings have proved they aren’t done yet and are on course for a remarkable reunion in the Australian Open final.

In total, the Williams pair have played out eight Slam finals, with Serena leading Venus 6-2.

And with each now in the semi-finals in Melbourne – on opposite sides of the draw – there’s a real chance of a ninth meeting.

It’s an incredible story. Venus is soon to turn 37, and reached her first Slam way back in 1997. Serena is only a year younger, turning 36 this September, and she too made her first Slam final appearance in the previous century.

Serena’s desire to remain at the top in recent years will see her rightly regarded as one of sport’s – not just tennis’ – greatest competitors, while Venus’ ability to fight back from an autoimmune disease and remain a force at the sharp end must be given the greatest of respect.

But can they both reach this year’s Australian Open final?

It would cement their place in history if they could, but standing in the way of a Williams showdown are two of tennis’ lesser-known lights.

However, both Coco Vandeweghe and Mirjana Lucic-Baroni are out to make their own headlines.

Incredibly, at 25, American Vanderweghe is nine years younger than any of the other remaining semi-finalists, but while experience has won it for the majority Down Under, the New Yorker has enjoyed her best Slam yet.

Despite heading to Melbourne in suspect form, Vandeweghe dispensed with 15^th seed Roberta Vinci in the opening round, and former Wimbledon finalist Eugenie Bouchard was ditched in round three.

But the scalp of world number one Angelique Kerber in the fourth round really made people stand up and take notice.

Reigning French Open champion Garbine Muguruza – still yet to convince on hard courts – was then dealt with in the last eight and now Vandeweghe is one-half of an anti-Williams brigade.

And looking to defeat Serena is Lucic-Baroni, who is in her first Slam semi-final since 1999.

Amazingly the pair haven’t met since Wimbledon in 1998, in what must go down as a record-gap between Slam meetings.

The Croatian’s path to the final four was blown wide open after her stunning victory over third seed Agnieszka Radwanska in the second round.

Upsets elsewhere ensured the 34-year-old didn’t face another seed until the quarter-finals, but Karolina Pliskova was similarly downed in three sets.

It’s a remarkable tale for a player tipped for greatness after reaching the semis at Wimbledon aged just 17.

So, how’s it going to shake out?

We make Serena 1/8 to end Lucic-Baroni’s dream run, and after stepping it up a notch to defeat Johanna Konta, it’s hard to back against the American.

But will Venus join her younger sister in the final? Our odds make her the outsider at 5/4, with Vandeweghe 8/13.

But the five-time Wimbledon champ has over 22 years of professional tennis to call upon, and has made fewer double faults and unforced errors than her opponent.

It’s been 14 years since the Williams sisters contested the 2003 Australian Open final, and though a lot has changed since then, Venus and Serena are on the cusp of taking us all the way back.

All Odds and Markets are correct as of the date of publishing