Defending champion Mark Williams suffered a worrying health scare after the opening session of his second-round tie with David Gilbert at the World Championship.

Williams lost the session 5-3 and later posted on social media that he was in the A&E department of a local hospital due to chest pains.

The 44-year-old informed tournament officials of the issue after the session and was advised by the on-call doctor to attend hospital. Williams made his own way there and is understood to be with his wife Joanne and son Kian.

Breaks of 105, 66 and 58 had earlier helped Williams get back on level terms against Gilbert, but the latter took the last two frames of the day to carve out a 5-3 lead.

Their last-16 match is due to resume at 10am on Saturday at the Crucible.