This was the first singles tournament of her comeback, and she arrived with no official ranking and no seeding, which explains how she and the 8th-seeded Venus wound up facing each other in the third round.
Indian Wells marks Serena's first WTA sanctioned tournament in 14 months after she gave birth to her daughter, Alexis Olympia Ohanian Jr., on the first of September past year.
Venus closed out the 29th career meeting between the two on her second match point as Serena sailed a forehand long to end the third round match.
This return to tennis was such a big deal that Serena's husband, Reddit founder Alexis Ohanian, 34, took out a series of four billboards along the I-10 freeway leading from LA to Indian Wells welcoming her back.
She will now take on No. 21-seeded Anastasija Sevastova in her next match with a spot in the quarterfinals on the line.
Wozniacki had been one of seven women who held the No. 1 ranking who hadn't won a Grand Slam when she triumphed in Melbourne in January. "She kept roaring back, I'm just lucky that I've played more matches than her right now".
Venus Williams (R) of the USA hugs her sister Serena Williams (L) of the USA after defeating her in their match at the BNP Paribas Open tennis tournament at the Indian Wells Tennis Garden in Indian Wells, California, USA, 12 March 2018.
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Green's hoop happened after he appeared to attempt a lob pass that hit off the backboard and caromed right back to him. Bell, who sprained his right ankle Tuesday against Brooklyn, will be out through the weekend and re-evaluated Tuesday.
The crowd's treatment led to a 14-year boycott by the sisters, which Serena finally ended in 2015.
But eighth seed Venus was a different proposition for Serena, who cut a frustrated figure as was broken in the sixth game - the 36-year-old lacking the fluidity and accuracy to asset her authority.
"That's, you know, totally gone out of my mind". First of all, 17 years ago seems like forever ago.
She fell behind 3-1 early in the second set but rallied by holding serve in the fifth game. She emphatically closed out the 36-minute set with back-to-back aces that clocked 108 miles per hour and 120 miles per hour.
"Being older again than Serena, myself, it's wonderful to see and I'm very happy for them, you know, especially now watching Serena's comeback since the baby", Federer said. I really abhor every time we play, but I do enjoy the battle when I'm out there. "It's just afterwards I don't like it as much".
The sisters were supposed to play each other in the desert in 2001. Serena leads 17-11 - and has claimed five of their past six meetings. "I'm getting there. It's not exactly where I want to be, but I'll get there eventually".