What was potentially a huge day for British fencing began poorly with Husayn Rosowsky losing his first-round match at the ExCeL and needing treatment.
The 21-year-old from Sheffield went down to Tunisian Mohamed Samandi, ranked two places lower than him at 58th in the world, 15-8 after suffering a hamstring injury midway through the fight.
The contest was stopped for nearly 10 minutes at 12-6 and Rosowsky managed to take it into the final three-minute period, but could not find a way back.
That left hopes pinned on Britain's top two. Richard Kruse, a quarter-finalist in Athens eight years ago, and rising star James-Andrew Davis received byes into the second round and were entering the fray at lunchtime.
Britain has not won a fencing medal since 1964 and has yet to see one of its squad make even the last 16 so far this week.
Rosowsky said: "I had a bit of a hamstring injury - it happened about a week ago - but didn't think it would bother me. As soon as I did my first lunge about a minute and a half into the contest I could feel it.
"I could have been better, but I'd not fought him before and he was very good. He surprised me. That's the way things go in sport. Hopefully it's fine for the team event on Sunday."
Rosowsky, Kruse and Davis are the three-man team, but reserve Laurence Halsted, the son of two Olympic fencers and the 2008 European silver medallist, can be brought on.
The day went from bad to far worse when Kruse lost 15-5 to Russian Artur Akhmatkhuzin, ranked six places lower than him at 21st in the world, in what had to rank as the biggest disappointment of his career.
Davis was on at the same time and trailed Germany's four-time world champion Peter Joppich 6-4.