O’Sullivan won seven of the eight frames played yesterday to extend his advantage from 6-2 to 13-3 in the best-of-33 frame contest.

Hendry has produced stunning revivals in the past, most notably in the 1992 world final when he broke Jimmy White’s heart in recovering from 14-8 down to win 18-14.

But it would take something remarkable on Saturday to overhaul O’Sullivan in his present form. He amassed two centuries and eight 50-plus breaks in the first 16 frames of the match.

Parrott said: “I’ve seen people focussed for three or four frames at a time like Ronnie was – but not for the entire session.

“It would not have mattered who was sitting in the opponents’ chair. It was magnificent, awesome. No-one can play better than that.”

Hendry had even been in danger of suffering his first-ever session whitewash at Sheffield until he won the final frame.

But the 35-year-old will have to win five of the next eight frames or he will taste defeat with a session to spare at snooker’s most famous venue for the first time.

Hendry is also under serious threat of experiencing his heaviest-ever defeat, which is currently the 9-0 drubbing handed out to him by Marcus Campbell in the first round of the 1998 UK Championship.

The Scot did not help his cause by making some uncharacteristic errors, missing relatively easy pots and also being guilty of poor safety play – but almost every one was punished in devastating fashion by O’Sullivan.

He accumulated 630 points to Hendry’s 138 during the session and his 12th century of the tournament took his world tally to 63 – only three behind second-placed Steve Davis in the all-time list.

On this form, neither Graeme Dott nor Matthew Stevens will have much chance of preventing O’Sullivan from adding to his 2001 title triumph on Sunday and Monday.

Bookmakers Ladbrokes have now made O’Sullivan 250-1 on to close out the match and 6-1 on to capture the title.

O’Sullivan’s likely overwhelming victory will be particularly sweet given his bitter rivalry with Hendry and the fact he has never beaten him at Sheffield in three previous meetings.

In the other semi-final Dott held his nerve after an onslaught from Stevens to move to within touching distance of his first World Championship final.

Dott looked to be finally bowing to the challenge of Stevens who reeled off four successive frames to move ahead at 11-10 for the first time.

But the 26-year-old gave every indication that he will not buckle as he won the final three frames of the third session to lead 13-11.

Now Dott will need to win only four of the remaining nine frames to cross the finishing line and secure his place in the top 16 for 2004-2005.