The 35-year-old overcame her sister Venus 6-4 6-4 on Saturday to claim her seventh Melbourne crown and secure an Open-era record 23rd grand slam title.
It means she moves above Steffi Graf in the all-time list and now stands just one short of Margaret Court's unmatched 24.
And Williams shows no sign of slowing. She has won 10 major titles since turning 30 and has made eight out of the last grand slam 10 finals.
She believes she is in the form of her life.
"I was thinking yesterday on the practice court, 'gosh I'm playing better than I have ever before I think'," Williams said.
"I'm moving better, I've always been a fast mover but I stopped moving a bit in the middle of my career because I was like, I don't have to move so much.
"But I was like, 'man I'm hitting really well'. It feels good to be playing this well at the moment."
By her own high standards, 2016 represented a disappointing season for Williams.
The American only added a Wimbledon title to her tally and also surrendered the world number one spot to Angelique Kerber after a shock US Open defeat to Karolina Pliskova.
"Winning this one was very important," Williams' coach Patrick Mouratoglou said.
"I feel when you end the season with a loss, especially in a grand slam, you cannot feel the same way and cannot have a good feeling.
"She had confidence but not the same kind as when you win. That's why this one was very important for the rest of the season."
Williams has struggled at times with the weight of expectation, crumbling at the 2015 US Open when a calendar grand slam was in sight and then stumbling again there in September when on the brink of breaking Graf's record.
She has appeared far more relaxed in Melbourne, on and off court, with her new fiance Alexis Ohanian here supporting from her box throughout.
"I've been trying to live it for some time now, this tournament I was able to do it," Williams said.
"I was okay with not losing but I also knew I didn't have to win here to make my career. It settled with me this time. I don't know why I felt like that but I want to know because I want it again."
Surpassing Graf's 22 major triumphs adds statistical weight to the now almost indisputable argument that Williams is the greatest female player of all time.
She could pass Court's mark at Wimbledon this summer, although 13 of the Australian's 24 successes came before the Open era, when grand slams were still not fully professional.
"Graf's record is more important because with all the respect for Margaret Court, it's another era," Mouratoglou said.
"The draws were like 16 players, they were not professionals. Of course the record is there and we definitely want to beat it but there is a professional era and the record was Steffi Graf.
Serena was not motivated by 22, she was motivated by grand slams. That's her motivation.
"This won't change until one day she wakes up and is not motivated to win grand slams but for now she is, so that's enough.
"Is that day close? I don't think so. I am not in her head but I don't think so."
'I never felt like number 2'
Williams did take some motivation from reclaiming her place at the top of the world rankings, which she will when the list refreshes on Monday.
To avoid adding any extra pressure, however, Mouratoglou told his charge at the start of the tournament that victory would not return her to number one.
"In the beginning of the tournament, I was like, 'if I win, will I be number one?'" Williams said.
"Patrick said, 'no, no, no.' So I was like whatever. Then on the court when they were said, 'and number one', I was like, 'whoa, really'?"
Williams later added: "Kerber played unbelievable, she definitely deserved to have that position. It didn't hurt or p*** me off, to me it just looked weird. I'd never felt like number two."