Luke Littler and Rob Cross came through starkly contrasting quarter-finals to set up a last-four showdown at Alexandra Palace.
Littler averaged over 101 in a dominant 5-1 victory over Brendan Dolan, who was poor and failed to ask serious questions of the 16-year-old beyond winning the first two legs of the match.
Cross on the other hand fought back from 4-0 down against Chris Dobey to win 5-4 after a sudden-death shootout, a phenomenal comeback from the former champion who had looked set for a swift exit.
It means that Littler will face his second world champion during this dream run to the semi-finals, and is now six sets away from Wednesday's final and a shot at history.
'It's going to take a lot to stop me'
"It feels unbelievable. I would never have thought I would have got to the semis on my debut year," he said.
"Brendan was just another opponent in my way and I have brushed him aside and now I am into the semi-final.
"It’s going to take a lot to stop me, based on my performances so far. But it is about whatever Luke Littler turns up.
"I have got the ability to go all the way, if it’s not to be tomorrow night, it’s not to be.
"I know I have got a good chance and I have got a good feeling I could go all the way tomorrow."
'I thought it was over'
Cross found himself 4-0 down following a blistering start from Dobey, and survived a match dart at the bullseye on his way to a memorable fightback.
A dramatic finale saw the deciding set go to a tie-break, and after Dobey missed 71 to level in the eighth leg, Cross took out 70 to keep his hopes of a second World Championship title alive.
"I really can't put it into words," Cross reflected. "Realistically, at 4-0 down I thought it was over, which is unusual for me.
"Chris settled much better than me in the early stages, he's an unbelievable player.
"I'm never beaten, whoever I play in the world. I'm similar to Nathan Aspinall in that respect, I never go away.
"As I got closer to Chris I thought 'this is on' because I knew my best was still to come in the match.
"I will have to improve and settle quicker to win the tournament, but I believe I can win it."
In the evening, Michael van Gerwen was dumped out by Scott Williams, but there was no such drama as Luke Humphries went up another gear to beat Dave Chisnall.
Read more about those matches here.
World Darts Championship 2024: Monday results & Tuesday schedule
Monday January 1
Afternoon Session (12.30pm GMT)
Quarter-Finals (Best of 9 sets)
TV Coverage: Sky Sports Darts
- Chris Dobey 4-5 Rob Cross
- Luke Littler 5-1 Brendan Dolan
Evening Session (7pm GMT)
Quarter-Finals (Best of 9 sets)
TV Coverage: Sky Sports Darts
- Michael van Gerwen 3-5 Scott Williams
- Luke Humphries 5-1 Dave Chisnall
Tuesday January 2
Evening Session (7.30pm GMT)
Semi-Finals (Best of 11 sets)
TV Coverage: Sky Sports Darts
- Luke Littler v Rob Cross
- Scott Williams v Luke Humphries
Fast Results
Scores
