But a dominant performance saw her beat Germany's Angelique Kerber in straight sets to claim the Wimbledon title and tie the record. Among those sitting in her family area were Beyonce and Jay Z. Sitting in the royal box were Ellen DeGeneres and wife Portia de Rossi, and retired players Martina Hingis, Tracy Austin, Billie Jean King and Navratilova.
Keeping her signature braids, Bey wore a white lace outfit with a high collar, while her husband Hov matched her in a white T-shirt.
Turning 35 in September and already women's tennis's oldest major champion, Williams admits she's hungry for more after equalling Steffi Graf's 22 singles slams, the most in the 48-year professional era.
Williams lost to Kerber in the final at this year's Australian Open and was beaten by Garbine Muguruza in the final of the French Open. "No, that's not going to shake me, you're not going to break me, it's going to make me stronger".
Just as she did in Melbourne, the German held her ground on the baseline and served smartly to keep Williams off balance.
On matching Graf's Grand Slam record, she added: "It's been incredibly difficult not to think about it. It makes the victory even sweeter to know how hard I worked hard for it".
Williams, 34, did it, as she often does, with almost impeccable serving. I felt I can do better, not only I can do this but I am going to do this and there is nothing in this world that is going to stop me'.
The world No 1 is two short of Margaret Court's all-time record of 24 Grand Slam victories
"Time heals", said Williams' coach, Patrick Mouratoglou. Last nine months have not been easy for Serena, it all started with the US Open loss to Roberta Vinci. "I have definitely had some sleepless nights, if I'm just honest, with a lot of stuff".
'I was just talking through things and how I was disappointed I lost the French and what I needed to do better at Wimbledon, ' Williams said. "I've never been so close to having something and then losing it. I also just feel like I've let a lot of people down".
The American siblings won their sixth doubles championship at the All England Club and 14th as a pair at all Grand Slam tournaments by beating fifth-seeded Timea Babos of Hungary and Yaroslava Shvedova of Kazakhstan 6-3, 6-4.
With a depth that might baffle normal humans, she had suffered the thwarting of her bid for a calendar Grand Slam. "But maybe even more so is the excitement of getting 22, trying so hard to get there, finally being able to match history, which is pretty awesome", she said.
It had been four years since the Williams sisters featured in a major doubles final - their victory at the 2012 Wimbledon Ladies Doubles Championships was the last time they reached this stage. I missed the moment.
Cherry on the cake for Serena Williams as she conquered another magnificent Wimbledon campaign by teaming up with sister Venus. And still she goes on, her record in major finals now an incredible 22-6.