Williams squandered four match points and a big-third set lead in a dramatic 6-4 4-6 7-5 quarter-final collapse against Karolina Pliskova on Wednesday.

But unlike her last grand slam loss, when the American's bitter exchange with the chair umpire at last year's US Open stole the spotlight from Japanese history-maker Naomi Osaka, Williams was magnanimous in defeat.

The 37-year-old refused to blame either an untimely foot-fault called on her first match point, nor an ankle injury suffered midway through the third set, for her crushing loss.

"My ankle seems to be fine. I usually don't know until the next day, so I think she just played lights out on match point, literally, hitting lines. Just went crazy," Williams said.

"I can't say that I choked on those match points. She literally played her best tennis ever on those shots."

The seven-times Open champion's exit comes after she also lost to Angelique Kerber in last year's Wimbledon final.

But still only 10 months into her comeback after giving birth to daughter Olympia in September, 2016, Williams remains confident a 24th career major will happen.

"The big picture for me is always winning. I'm not going to sit here and lie about that," Williams said.

"But it hasn't happened yet, but I feel like it's going to happen. I'll just keep taking it one match at a time, just keep soldiering on."

Also claiming to be as hungry as ever, Williams pointed out how difficult it had been to firstly match the long-time benchmark of 18 slams of Chris Evert and Martina Navratilova, then Steffi Graf's open-era record of 22 majors.

"Twenty-three wasn't close, but 22 was close for a long time," she said.

"Eighteen was close forever. Yeah, we'll see."

Australian Associated Press