Whatever doubts persisted around Serena Williams’ fitness and taste for the fight in her quest for a seventh US Open title and record-tying 24th major championship were brushed aside in stunning fashion on Friday night as she romped to a 6-1, 6-2 victory over her sister Venus in a scant 72 minutes before an electric crowd at Arthur Ashe Stadium.

Serena, the No 17 seed in a tournament she’s won six times but not since 2014, one slot below Venus on the drawsheet, equaled her most lopsided victory in 30 professional meetings with her most inconvenient rival, overcoming an early injury scare to roar into the second week of the season’s final grand slam on a full head of steam.

Playing on the outsized stadium court where they’d waged consecutive US Open finals in 2001 and 2002, Venus winning the former and Serena the latter, the younger sibling who became a 23-time grand slam champion unleashed a beatdown so one-sided and comprehensive it at times felt uncomfortable for a jam-packed crowd expecting something resembling an even fight between the two most decorated players of their generation.

“This was my best match since I returned,” said Serena, who improved to 18-12 against Venus and 11-5 in grand slam matches. “I worked for it. I worked really hard these last three or four months. That’s life, you have to keep working hard no matter ups or downs you have. That’s what I’ve been doing.”

It was the earliest they’d faced one another in a tournament since Venus prevailed in the second round of the 1998 Australian Open in their first meeting on the women’s tour, but what Friday’s main event lacked in competitive ballast it made up for in a ceremony pregnant with nostalgia. The asking price for a ticket in the 22,547-seat behemoth in Flushing Meadows, the largest tennis stadium in the world by acres, which traded for less than $90 on the secondary market on Wednesday as the sisters played their second-round matches, soared upwards of $300 in the hours before they took the court.

To be sure Venus-Serena XXX was a moment, a very American moment, two great lions in winter in internecine combat, and for the first time in a minute given Serena’s precarious form entering the tournament the outcome was in doubt.

Yet the one-way traffic that unfolded on Friday night didn’t come close to matching the promise of the evening as Serena, who won seven games on the trot after receiving treatment for an ankle injury during the first changeover, crushed 10 aces to just one for Venus.

One after another Serena pounded deep, heavy groundstrokes that prevented Venus from attacking and moving forward, negating the length and elegant play that’s made her a seven-time major champion and no worse than the second best of her era. To behold it made you wonder if Serena at this point knows Venus’s game better than Venus, 38, knows it herself.

“I think it’s the best match she’s ever played against me,” Venus said. “I don’t think I did a lot wrong. But she just did everything right.”

The idea of a Williams v Williams showdown has from the jump been superior to the matches themselves, which are typically tense, awkward affairs. Friday’s was no different.

“Every time she loses, I feel like I do,” Serena said in the immediate aftermath.

A trainer works on Serena Williams’ ankle early in Friday’s match. Photograph: Julio Cortez/AP

Venus had been a household name even before her breakthrough run to the 1997 US Open final, landing the cover of Sports Illustrated amid a deluge of Madison Avenue suitors. And while Serena was first to a major title (the 1999 US Open), the tour belonged to Venus in 2000, when she won at Wimbledon and Flushing Meadows, along with Olympic gold in Sydney, rattling off a streak of 35 consecutive wins.

Even the kid sister was no match in those days for Venus, who won five of their first six matches including the 2001 US Open final. But Serena 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.

No player on tour has recorded more victories over Serena than Venus’s 12. But Serena has won 17 of 24 meetings since her sister’s opening salvo, including seven of eight in major finals.

This one was not supposed to be so easy for Serena, who turns 37 next month and is playing in only her seventh tournament back since giving birth to her daughter a year ago on Saturday. Alas.

The jettisoned NFL players Colin Kaepernick and Eric Reid were among the audience, and were cheered passionately when showed on the big screens late in the second set long after the outcome in doubt, sealing the night as a celebration of blackness.

But Friday’s outcome more than anything showed Serena, now four wins from a historic triumph on the court where she broke her grand slam maiden, is as ready as ever to not merely compete but make good on the oddsmakers’ optimistic tack.