England’s Reanne Evans lost 6-3 to compatriot Andy Hicks in a televised World Championship first-round qualifying match in Sheffield.
Evans, 34, was bidding to become the first woman to win a televised match at a ranking event.
The rescheduled championship event starts on 31 July at the Crucible.
“I’m disappointed because I felt good – but with maybe a couple more weeks’ practice I would have been more match sharp,” Evans said.
“I expected Andy to be more aggressive so I was a little shocked.”
The qualifiers, at the English Institute of Sport in Sheffield, began on Tuesday and run until 28 July.
In November 2019, Evans came within a frame of becoming the first woman to beat a man in snooker’s top 16.
Evans fought back against world number eight Shaun Murphy, before losing 4-3 on her Champion of Champions debut.
Hicks, 46, reached the semi-finals at the Crucible in 1995, but has not qualified for the Championships since 2007. He plays Sam Craigie in the next round of qualifying.
Meanwhile, six-time runner-up Jimmy White, 58, begins his bid to reach the main draw when he plays Russia’s Ivan Kakovskiy at 20:00 BST on Tuesday.