A decade or so ago, Serena and Venus Williams ruled tennis together, swapping the No. 1 ranking and meeting in Grand Slam final after Grand Slam final.

Serena, the younger of the pair, still holds a spot at the top of the game.

Venus has not been there for quite some time.

So there was a turn-back-the-clock feel to Day 1 at the 2013 U.S. Open, when both sisters were about as good as can be, dropping a combined four games in Arthur Ashe Stadium.

Venus, now ranked 60th, beat 12th-seeded Kirsten Flipkens 6-1, 6-2 on Monday afternoon, and then Serena reduced 2010 French Open champion Francesca Schiavone to seeking comfort from a ball boy’s hug during a 6-0, 6-1 runaway under the lights at night.

Asked which meant more on this day, her own victory or her sister’s, Serena replied, “They’re equal. I definitely was happy to see Venus win. I really was happy for her. I know she’s been working hard. I know she had a tough opponent. For her to come through was just awesome. Obviously, I want to do well, too.”

For years and years, a first-round victory by Venus at a major tournament would hardly merit a mention. She has won seven Grand Slam titles and was the runner-up another seven times (six against Serena).

And yet nowadays, at age 33, two years removed from being diagnosed with an autoimmune disease that saps energy, hampered much of this season by a bad lower back, Venus entered this U.S. Open having won a total of three matches over the past five major tournaments. Plus, in Flipkens, she was facing a semi-finalist at Wimbledon last month who beat Venus on a hard court this month.

Looking very much like the player she used to be, Venus smacked serves at up to 120 mph, returned superbly, and covered the court well enough to hit a handful of swinging volley winners.

“If Venus is there if she’s fit, if she’s focused she’s a top-10 player,” Flipkens said. “Everybody who knows a little bit of the game of tennis can see that. Today, she was like a top-10 player.”

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