"No matter what happens, I can't lose, she can't lose," Serena Williams said after her semifinal victory on Friday set up a first Grand Slam final meeting with big sister Venus since 2009. Of course, in a sporting sense, she was wrong – but the women’s singles final here in Melbourne this year was never just about sport.

That may seem counter-intuitive, given that it featured two of the greatest athletes of the modern era, and that this match was played in one of sport’s great arenas. But the story of the Williams sisters is as much about family ties, durability, and overcoming adversity as it is about sporting greatness.

The embrace that the sisters, now in their mid-30s, shared after Venus’s last backhand dropped into the tramlines to hand Serena a 6-4 6-4 triumph proved that even when sporting history is being made, sisterhood matters more.

"That’s my little sister, guys," Venus told the crowd in her post-match address, beaming in Serena’s direction. For two girls that started their tennis journeys on public courts in Compton, the fact that they continue to face-off on the sport’s biggest stages nearly two decades after bursting on to the scene as a pair of confident and supremely talented teenagers is nothing short of remarkable.

"Still to this day we work side-by-side each other at practice. We motivate each other," Serena said later. "The motivation she gives me, it's really second to nothing. It's amazing."

The match itself started nervously, as these clashes often do, with the first four games going against serve and neither player able to establish much of a rhythm. It wasn’t until Serena belted a backhand winner in the seventh game to move 4-3 ahead that the six-time Australian Open champion looked to be in control.

Venus held firm to force Serena to serve it out, and the younger sister made no mistake, holding confidently to love to take the opening set.

The seventh game proved to be crucial in the second set, as Serena once again made the decisive move, getting the better of a 16-shot rally to set up break point and, although Venus saved the first, the pressure ultimately told and Serena had the breakthrough.

Three games later, with ball in hand and history on her racket, she withstood pressure from Venus to win 4 straight points from 0-30 down, then collapsed to the ground – the title that had been wrested from her last year was hers once more.

"It's such a great feeling to have 23," she said in her post-match press conference. "When it got on my radar, I knew I had an opportunity to get there, and I'm here. I'm here."

Her path to 23 has not been without struggle. After winning the first three majors of 2015, she was widely backed to go all the way and record the ‘calendar-year Grand Slam’ to add to the two ‘Serena Slams’ (holding all four Grand Slam titles at once, but not in a calendar year) she had already achieved.

But expectation does funny things to even the most talented of athletes, and losses to Roberta Vinci, Angelique Kerber, Garbine Muguruza and Karolina Pliskova have made Serena’s wait to match then surpass Steffi Graf’s Open Era record for most Slam titles a tough one. At least a small part of her joy in winning this title must be the relief that the Graf-comparisons will be at an end.

Venus, too, has had her struggles. Competing at the highest level while dealing with the autoimmune disease that she was diagnosed with a few years ago is a stunning achievement – let alone reaching Grand Slam finals. She will no doubt be able to take a huge number of positives following her first run to a major final in over seven years.

"That's exactly where I want to be standing during these Grand Slams, is on finals day, having an opportunity," she reflected later. "That's the highlight of all this, to be in that moment."

But back to Serena and the question of what next. Attention will inevitably turn to Margaret Court’s all-time record of 24 major titles. Only when she passes that (and it does seem that it is a matter of 'when' not 'if') will the tennis fan’s favourite bar-room debate – the infamous 'greatest-of-all-time' question – be decisively settled.

Serena won’t care about that. She might, however, be pleased that she will return to No. 1 in the world when the new rankings are released on Monday. But most of all, she will be thrilled to have shared one of the biggest stages in the tennis with her big sister once more.

Serena was right – it really felt like there were no losers tonight.