Whereas the American was defeated by crafty veteran Roberta Vinci 12 months ago to end hopes of a rare calendar-year slam, an ailing Williams lost to big-hitting Karolina Pliskova 6-2 7-6 (7-5) on Thursday in New York.
She'll thus have to wait to become the first player in the Open Era to win 23 majors -- Williams is currently tied with Steffi Graf on 22.
And in a double blow, when the new rankings are released Monday, the 34-year-old will lose top spot to Angelique Kerber, ending Williams' record-tying -- with Graf -- 186th straight week at No. 1.
It certainly wasn't vintage Williams about 24 hours after she outlasted Simona Halep in a slugfest and she told reporters post match Thursday she was dealing with a left-knee injury.
It would explain some of her unusual statistics against Pliskova, who plays Kerber in Saturday's finale. Knowing she locked down the No. 1 ranking even before her match started against Caroline Wozniacki, the German appeared bolstered and downed Williams' good friend 6-4 6-3.
