Any lingering doubt that Ronnie O'Sullivan might not have the form or the temperament to land a fourth Betfred.com World Championship title was emphatically dispelled.
O'Sullivan crushed Neil Robertson's title dream with some exquisite play in the evening session of their quarter-final to close out a 13-10 victory over the Australian.
At the age of 36 years and three months, O'Sullivan would become the oldest world champion since 45-year-old Ray Reardon triumphed aged 45 in 1978 should he triumph on Monday.
Matthew Stevens stands in his way of a first appearance in the final since 2008, when the game's most thrilling player lifted the Crucible trophy for a third time.
If O'Sullivan produces the form he showed in afternoon and evening sessions on Wednesday, the man from Carmarthen will surely be denied a third appearance in the final.
Robertson had little answer to O'Sullivan's brilliance as the Chigwell showman won the opening six frames of the day to surge from 5-3 behind to 9-5 in front, aided by breaks of 44, 47, 97, 62 and 42.
He looked sure to make a century in the second frame of the afternoon but fell three points short, seeming to refuse the chance of a ton after failing to execute a kiss on a red quite as effectively as he wanted.
Rather than play a double, O'Sullivan nudged the white off the red and into the middle pocket.
Robertson took the final two frames of the afternoon, the second with a morale-boosting break of 63, his previous highest of the session having been a mere 29.
The world number three began the evening session with purpose too, rattling in a break of 50 to narrow the gap to one frame.
If O'Sullivan was worried, he was giving nothing away.
Robertson gifted him an opening chance from a poor break and in went an immaculate 104, followed by 71 to establish a position of authority at 11-8.
Seeking a swift resolution, O'Sullivan sprinted to a round break of 100 before missing the yellow to close to one frame way from victory.
Robertson was not finished and made it 12-9 with a run to 89, perhaps seeking inspiration in Ali Carter's fightback from the same deficit to beat Judd Trump in the second round.
And a 77 break from Robertson, who has set up home in Cambridge since joining the professional ranks nine years ago, briefly complicated O'Sullivan's task.
Robertson's hopes were soon snuffed out though, O'Sullivan rattling through another high-speed break, this time a 59, to make victory safe.
Stevens completed the remarkable turnaround in his all-Welsh Crucible quarter-final against Ryan Day as he clinched a 13-5 victory.
The two-time former beaten finalist at the Betfred.com World Championship trailed 5-2 at one point, but won 11 frames in a row to advance - nine on Tuesday night and two on Wednesday morning - as Day's game deserted him.
"You've got to be fearless and get in there and try to win, and I managed to do that, but it was a disappointing match," said the Welshman.
Now a sixth World Championship semi-final and a first since 2005 awaits the 34-year-old, who has revived his career after a slump which saw him fall outside the top 16.
"I'm so excited," Stevens said. "It's been a long time."
"A lot of people probably didn't think I'd be in this position again, but a lot of hard work and self-belief and I'm here again.
"I'll be the underdog in the semi-final but I think that'll suit me.
"I'd be lying if I said I thought I'd never be back in the semis or the final.
"But a few years ago I was in the thirties or maybe forties in the rankings.
"It was tough, playing a match every six weeks and not practising. It wasn't looking great, but since Barry (Hearn) has taken over it's given me a new lease of life, and I enjoy practising now and I enjoy competing. We're playing every week and that's what I needed."
Welsh qualifier Jamie Jones' Crucible debut finally came to an end when he was edged out 13-11 by Ali Carter, who will play Hendry's quarter-final conqueror Stephen Maguire next.
Jones, a 24-year-old from Cimla near Neath, said: "I scored really well but couldn't really get enough chances because my safety was that bad."
He was pleased to win two rounds in Sheffield though, and said: "I genuinely feel I can win an event now."
Carter said of Jones: "He's an awesome player, gutsy as you like. He reminds me of Graeme Dott, he's always on your heels."
Battling Crohn's disease, an inflammatory bowel disease, Carter has cut back on dairy and wheat products and reported the new diet was working well early in the tournament.
But he tonight said against Jones he was struggling health-wise.
Carter said: "I've felt terrible really this last day or two. I went out and ate a steak and I think it was too heavy, so I've got the bloatedness back and everything like that.
"I had it from the start of this match but I was so determined that it wasn't going to affect me."