There is by now a numbing effect to the decades‑long dominance of Serena Williams, who on Saturday captured the Australian Open championship for a seventh time to eclipse Steffi Graf’s record for major titles in the Open era, all but silencing the few stubborn holdouts who referred to the record book to deny that she is the best there has ever been.

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There was no congratulatory phone call from President Donald Trump like the one she had taken from Bill Clinton in 1999, shortly after the precocious 17-year-old from Compton had become the first black woman to win a grand slam title in more than four decades. Now the trophies, even as they are collected at a more advanced age than anyone in the modern era, have become expected and matters of routine. The fanfare back home, where Saturday’s final took place in the middle of the night, was relatively subdued, dwarfed fairly by a nation’s existential self-reckoning in the wake of a ban on immigrants that has registered shockwaves worldwide.

It is still only a tennis match. Yet there could be no more compelling metaphor for what makes America great than what took place on Saturday at Melbourne Park: two black female Jehovah’s Witnesses from south central Los Angeles in the winters of their panoramic careers, who came from nothing and honed their craft on cracked public courts and persevered in the face of racism, sexism, illness and family tragedy to rewrite the history of a sport predominantly owned, played and watched by society’s privileged. Champions of the marginalised shining on the world stage.

The defining point of the final came late in the proceedings with Serena serving for the championship at 5-4, 15-all – three points from the title and the No1 ranking that she had ceded four months earlier. The two finest and most important players of their era traded hellfire from the baseline over 24 strokes – the longest rally of the night – a pitched battle finally settled when Venus briefly wrong-footed her sister with an inside-out forehand tracer that painted the line.

It was an exhilarating display of the athletic power-baseline tennis the sisters’ arrival harkened at the turn of the century, then a stylistic leap forward that dared their contemporaries to evolve or die. The exchange left Serena breathing heavily as the crowd roared in approval. But the younger of the Williams tandem, as she has done countless times throughout a 22-year career, found her footing and rattled off the three final points, sealing the victory and denying her big sister an eighth grand slam title.

Play Video 2:11 Serena Williams beats sister Venus to win Australian Open – video highlights

It was only fitting that Saturday’s coronation took place on the same Rod Laver Arena court where they had first met as professionals in a second-round match at the 1998 Australian Open. By that time it was clear the braided teenagers were more than a novelty act, even if they had yet to blossom fully into the disruptive force that would collectively alter the sport forever.

Venus had been a household name even before her breakthrough run to the US Open final only four months prior, landing the cover of Sports Illustrated amid a deluge of Madison Avenue suitors. And while Serena was first to a major title in 1999, the tour belonged to Venus in 2000, when she won at Wimbledon and Flushing Meadows, along with Olympic gold in Sydney, amid a 35-match winning streak.

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Even Serena was no match in those days for Venus who won five of their first six matches including the 2001 US Open final. But the younger sister rapidly turned the tide with six straight victories, including the four consecutive grand slam finals that comprised the first of her two eponymous Serena Slams. “It’s like the No2 golfer in the world being Tiger Woods’ kid brother,” the analyst Mary Carillo said back then. “What are the odds?”

No player on tour has recorded more victories over Serena than Venus’s 11. But Serena has won 16 of 22 meetings since her sister’s opening salvo, including seven of eight in major finals.

It takes even hardcore tennis observers by surprise to realise Venus, given her outsized standing in the sport and first-name familiarity in culture at large, has spent a scant 11 weeks at No1 – fewer than all but one of the 22 women who have reached the top spot. Still, she has managed seven major titles and made herself known in even more influential ways, not least her lead role in the fight for equal prize money.

Their longevity in a sport notorious for burnout cases further sets them apart. Consider that Venus, battling the incurable autoimmune disease that has hamstrung her game for most of the decade, made it to Saturday’s final as the oldest player in the top 300, scoring wins over players nearly half her age. Or that Serena’s win made her the oldest player to win a major singles title in the Open era, breaking a record she set herself last year. And again the year before that.

It cannot be said they make for the most compelling matches and Saturday’s mostly drama-free affair was no exception. Styles make fights and their similar games too frequently neutralise one another, to say nothing of the awkward interplay of siblings forced into bloodless combat. But the sense of ceremony when the two most decorated players of their time face off is undeniable. In that sense there could have been no more appropriate foil for Serena’s final step into immortality than Venus, the flintstone that helped the younger sister lift her game to previously unthinkable heights.

“There’s no way I would be at 23 without her,” Serena said after Saturday’s historic win. “There’s no way I would be at one without her. There’s no way I would be anything without her.

“She’s the only reason the Williams sisters exist.”

Against all logic, still they rise. Only in America, indeed.