Mark Allen knows how it feels to beat Ronnie O’Sullivan on the big occasion — and it’s a feeling he wants to experience again tonight.

Allen beat the then defending World champion at the Crucible last April and a repeat in Newport tonight would see the Antrim cueman take a huge step towards a first ranking title.

The 23-year-old defeated former World Championship finalist Matthew Stevens 5-2 yesterday to book his place in the Welsh Open quarter-finals against World number one O’Sullivan.

But ‘The Rocket’ will start clear favourite tonight, boosted by yesterday’s 5-0 drubbing of Jamie Cope.

“Ronnie’s still the best player around and beating him in last season’s World Championship was a big confidence booster,” said Allen.

“Ronnie’s one of the players who are always there or thereabouts when it comes to winning tournaments.

“That’s the sort of level I want to be at and it would mean a lot to me if I could win the Welsh Open.”

The Ulsterman beat three-times World champion O’Sullivan 13-11 in the last 16 of the World Championship before losing to eventual champion John Higgins in the semi-finals.

O’Sullivan needed just 55 minutes yesterday to see off the challenge of Cope, who wasted quite a few opportunities against the Londoner.

“You expect all these players to clear the table, and when they don't you're surprised. He missed a few,” O'Sullivan said. “He had plenty of chances, but if he doesn't take then I'm capable of making a few.”

Defending champion Ali Carter faces Welshman Ryan Day this afternoon before attention turns to the big showdown between Allen and O’Sullivan.