Defending champion Ronnie O’Sullivan will need to get his head straight before taking on Mark Davis in the English Open semi-finals after an unfortunate incident in his last-eight triumph over Luo Honghao.

The five-time world champion secured a 5-3 victory over the young Chinese star but it was achieved in controversial circumstances as he accidentally committed a foul in the sixth frame which went unnoticed by the referee.

The 42-year-old brushed a red with his cue after potting a different red when using the rest, with neither the official nor the two players involved aware of what had happened.

It was picked up by the TV cameras and afterwards the Rocket was distraught and offered to replay the match.

“I didn’t even see that in a million years,” he said. “I’m happy to go play the match again if they want to. I feel awful after you showed me that.”

“I wish someone would have said something and stopped the match – that’s what they should do.”

That will not happen and the legendary cue-man is set to square off with fellow Englishman Davis later on Saturday evening for a place in the final.

The 46-year-old Sussex man eased through his last-eight encounter against Ryan Day with little trouble, securing a 5-1 success over the Welshman in Crawley. He said he was “over the moon” with his display and the result but will now face the ultimate challenge against one of the best players the game has ever seen.

O’Sullivan is priced at 1.15 to win, while Davis can be backed at 5.25 to advance to Sunday’s final.