Fergal O'Brien bowed out of the Northern Ireland Open on a day where Ronnie O'Sullivan progressed to the last 32 but claimed afterwards he was "bored".

O'Brien was whitewashed 4-0 by James Cahill, with the Welshman sealing his place in the second round with a round of 99.

Six-time world champion O'Sullivan defeated Andy Hicks 4-1, but was not impressed by the atmosphere at the Waterfront Hall in Belfast.

O'Sullivan compiled breaks of 76, 54, 65 and 90 along the way. Afterwards the six-time world champion was not impressed with the atmosphere at the Waterfront Hall.

He told wst.tv: "It was very flat out there. I was very bored. I just wanted to get out of there as quickly as possible."

Mark Selby kept his title hopes alive by the narrowest of margins after beating first-round opponent Cao Yupeng 4-3.

China's Cao cleared up to the final black in the decisive frame, but missed a difficult pot and left it over the pocket for world champion Selby to triumph.

Selby told wst.tv: "It was a tough shot to take on under the circumstances. I thought Cao played well from start to finish.

"I've always rated him, even when he was on the tour a few years ago. I knew I was in for a tough match before it started. I really enjoyed it, from a neutral's point of view I'm sure it was a good game to watch."

Three other former world champions, Shaun Murphy, Mark Williams and John Higgins, all progressed.

Murphy won his first-round match against Bai Langning 4-2, Williams edged past second-round opponent Elliot Slessor 4-3 and Higgins beat Farakh Ajaib 4-2 with breaks of 113, 85 and 54.

Kyren Wilson made scores of 127, 73, 51 and 120 in his 4-1 win against Robert Milkins and Masters champion Yan Bingtao hit back from 3-1 down to beat Duane Jones 4-3.

Luca Brecel, Oliver Lines and Mark King were among the other winners.