A handsome winning margin disguised what was a mediocre opening performance from the five-time champion, who was wearing a comfortable old pair of dress shoes for the finale to the contest, having risked a fine by briefly playing in his socks when a new pair were causing him pain on Tuesday.

It is understood O'Sullivan could face a small punishment, in the region of £250, for being in breach of the World Professional Billiards and Snooker Association's dress code.

He told BBC Two after clinching his last-16 place: "I've got no fashion sense at all. I had the last ones for 10 years - I didn't want to get rid of them and then I left them in a hotel and I lost them.

"I had this old battered pair, and I thought, 'I've got to buy a new pair', and I just bought the wrong pair basically.

"They were bashing my feet and I had to take them off. I couldn't wear them."

O'Sullivan borrowed shoes from tournament director Mike Ganley, who had warned him he required suitable footwear.

"He said, 'You cant play in your socks', but I didn't want to play in my shoes either," O'Sullivan said.

"I got a pair of Mike Ganley's stinky old shoes, and you know what - they felt great."

O'Sullivan began the two-session match with a break of 104, and added runs of 61, 59, 54 and 75 in establishing a 7-2 overnight lead, before doing enough in a scrappy morning session on Wednesday to cross the winning line and set up a shot at Matthew Stevens or Mark Williams in the second round.

However many chances O'Sullivan needed to win his frames, Steadman invariably obliged, with a string of missed blacks on Tuesday proving highly damaging. A more composed opponent would have punished O'Sullivan.

The first frame of Wednesday morning went O'Sullivan's way, as Steadman's missing ways persisted. It seemed the pattern would continue into the next too when Steadman missed brown for the frame.

However the 32-year-old lorry driver's son from Manchester had an unexpected reprieve when O'Sullivan overcut what looked a quite straightforward shot on the same ball, and this time Steadman made it count.

It was snooker from amateur hour at times, even from O'Sullivan, looking way off the game that has taken him to the last three World Championship finals.

As the mistakes from both men continued, O'Sullivan had a highest break of 27 to nudge 9-3 ahead, and snaffled the next to safely clear his first hurdle in the tournament.