Williams was trying to win her record-equaling 24th Grand Slam singles title, but she failed in a final for the third time. Simona Halep has nearly none of the pressure on her shoulders heading into her first Wimbledon final, and for Williams, that's a unsafe thing - Halep is at her best when she can play freely.
Williams has already had two failed attempts in finals to win that 24th major - after contesting last year's Wimbledon and US Open showpiece matches - and, regardless of what she says, everyone knows the American wants that record.
She has won seven of the 10 finals she's played in south west London and an eighth crown would see her draw level with Margaret Court as the most successful player in the history of women's singles.
Twitter users have mocked "mediocre white men" after a survey showed how many people think they could win a point off U.S. legend Serena Williams if they faced her in a game of tennis.
By contrast, Saturday's game was Halep's first final appearance at Wimbledon and, now, her only second Grand Slam title.
Williams, whose early part of the season was affected by a knee injury, said it was not just her and Woods who were enjoying extended careers.
Williams hasn't had too many challenges at Wimbledon during the Fortnight. "It's a day-today basis with me". It's not just me, it's Roger [Federer], Tom Brady, Peyton [Manning] played forever. "I would have gone for surgery even if I hadn't been a sportswoman".
As she trudged back to her court-side chair after just 20 minutes of play she must have felt like the earth was swallowing her up. But I knew there was no time for emotions. I have never played a better match. Or put a palm up and look at her guest box, as if thinking, "What can I do?" Now, if I face her, I will believe that I have my chance to win against her. Federer got to 63 such wins with his win over Nadal.
She finally got on the board with her next service game but Halep had little trouble in sealing the set which included another remarkable point from the Romanian. "So I'm definitely at a different place", said Williams.
"I was really calm", she said. "It's just about going out there and giving my best effort, no matter what".
"Simona has to get the first strike because when she's on the defensive, Serena will get closer to the baseline, and it will become that much harder to go down the line".