Williams ended the match with 26 winners – with 15 coming over the final 10 games – and 38 unforced errors, after hitting just three winners to 12 miscues in the opening set.
“I think in the first set she gave me a hell of a lot of cheapies, a lot of errors. Early in the second, in that game, at 1-0, she stepped it up a notch,” Barty said in defeat.
“I think there were only really a couple of games, a couple of my service games, but I don’t think there was really a hell of a lot in that match.”
Williams’ trademark service action started firing after she restored parity in the second set, to the tune of seven aces across sets two and three.
The 23-time major champion found her best in the final set on serve, as she landed 75% of her first deliveries, dropped just seven points overall and did not face a break point.
“It’s been a long way and a long journey, and I’m still getting there – but I have been working really hard for a really long time,” the American added.
“I just am hoping that every day I’m out there, every match I’m out there, hopeful it will come together.”