Reigning champion Mark Williams went to hospital with chest pains following the first session of his second-round World Snooker Championship match in Sheffield ©Getty Images

Reigning champion Mark Williams went to hospital due to chest pains following the first session of his World Snooker Championship second-round match in Sheffield.

The 44-year-old Welshman felt unwell having fallen 5-3 behind against England’s David Gilbert at the Crucible Theatre.

He was advised to go to hospital by a doctor at the venue.

"A&E. Could be hear [sic] a while, couldn't stick the chest pains no more," Williams tweeted.

"Lucky there wasn't any more frames to play."

Like Williams, three-time winner Mark Selby is also trailing.

Selby bounced back from 5-3 behind to lead fellow Englishman Gary Wilson 7-6 in the second round, but the world number 32 fought back to establish a 9-7 advantage.

Australia's Neil Robertson became the first player to reach the quarter-finals ©Getty Images
Australia's Neil Robertson became the first player to reach the quarter-finals ©Getty Images

The first player to reach the quarter-finals was Australia’s Neil Robertson, who thrashed England’s Shaun Murphy 13-6.

Robertson, the 2010 champion, was 10-6 ahead going into the evening session and his third century break of the match set him on his way to sealing victory.

He will play either England’s Stuart Bingham or Scotland’s John Higgins.

Elsewhere, Scotland's Stephen Maguire leads England's James Cahill 8-7.

Action is due to continue tomorrow.