John Higgins eased into the UK Championship second round with a 6-1 victory over Leo Fernandez, after a crowd member being treated for a seizure delayed play.
Spectators and both players initially thought the audience member had fallen asleep, before realising the situation was not so light-hearted.
A World Snooker spokesman confirmed a member of the crowd had suffered a seizure, but received treatment and made a full recovery.
The audience member was also thought to be planning to return for the evening session, by which time Higgins had long since toasted his first-round victory.
"At first I thought it was me on a plane, I can snore like that when I'm on a plane," said Higgins.
"I hope he's okay, I heard he had a bit of a seizure or something.
"I heard he was in a bit of a bad way and that it wasn't just snoring, so I hope he's okay."
Higgins hit a top break of 129 in a routine victory that tees up a clash with the winner of Tian Pengfei and Ian Burns in York.
"I've got a bit of confidence behind me from winning a couple of early-season tournaments, so I'd love to do well here," said Higgins.
"I've not really done well here at all, so I would love to have a good run."
Mark Davis eased past Rhys Clark 6-1, with Jamie Jones seeing off Ian Glover 6-4.
Stuart Carrington edged out Liam Highfield 6-4 while Martin Gould accounted for Allan Taylor 6-2 and David Grace eased past Andrew Higginson 6-1.
Ken Doherty blitzed Tony Drago 6-0, before admitting he hopes he can harness the enjoyment factor of playing in York.
"It's nice to play well and get in a bit of form," said Doherty.
"There's life in the old dog yet but finding that consistent form is the problem.
"I like it up here in York, it's a great venue and a great city.
"It was nice to play well, win and be in the hat for the weekend."