In the opening contest on a chilly, icy evening at Ally Pally, Littler maintained his winning streak over Searle and is still yet to lose a major televised semi-final in his career.
The match opened with promise for Searle, who claimed the first set through heavy scoring and composed finishing, momentarily puncturing the sense of inevitability that now follows Littler.
It was just a brief interruption, though. From that point on, control swung sharply and decisively towards The Nuke.
Littler responded by tightening every aspect of his game. His scoring surged, his timing sharpened, and crucially, his finishing held firm whenever Searle threatened to apply pressure.
Sets two and three slipped away from Heavy Metal through fine margins, missed chances punished instantly as Littler repeatedly tidied up on tops and double ten, refusing to offer a way back.
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The fourth set marked the moment the semi-final began to resemble a procession. Littler broke early with an 11-dart leg, absorbed a scrappy exchange on the doubles, then closed out another whitewash with clinical ease.
Seven legs in a row belonged to the reigning champion, his average climbing into the high hundreds as Searle was forced into survival mode.
Littler reeled off a 12-darter in set five, threatened perfection once more with six straight treble 20s, and even when he missed chances, the pressure never eased. Searle could not land the blows required to halt the momentum, and Littler moved to the brink without drama.
The finish carried a touch of theatre. Littler opened the final set with seven perfect darts, only for Searle to briefly light up the room by reeling in a superb 170.
Littler steadied, capitalised on a missed double from Searle, and with the match on the line showed maturity beyond his years, resetting calmly before pinning tops to seal a 6-1 victory and book his place in another world final.
'I can be better'
"The main goal is to go back to back," Littler told his post-match press conference.
"I never say I'm gonna win it. Never. We'll see how the darts go because one day it's different, and the other's not. Hopefully, with a good night's rest, we can go tomorrow.
"I think I could have done a bit better tonight. I obviously missed a few doubles. But I was very happy with the tops tonight.
"Usually, I'll come inside on purpose and hit the 10s. If it's over 50 per cent on the doubles, I'm happy because that's a key part, not only for myself but for every player on the tour.
"This is my third time here (in the final). I know how to win. Hopefully it's another win tomorrow night."
Littler averaged over 105 across the match, landed 10 maximums and converted his doubles with ruthless efficiency.
For Searle, this was a humbling end to a superb run, one in which he has pocketed £200,000 in prize money alongside earning a place in the top 10 in the rankings.
Littler moves on to the final once more, one match away from becoming just the third player in history to win back-to-back world titles and the first to clinch the recently-boosted £1 million winner's pot.
Van Veen stops Anderson
In the second semi-final, Gary van Veen won a thrilling encounter against Gary Anderson 6-3, a match featuring massive 170 checkouts, insane clutch play, and phenomenal maximum scoring.
In an elite encounter, both players averaged well north of the ton for long stretches, with Anderson at times appearing to turn back the clock entirely. However, Van Veen absorbed everything the two-time champion threw at him and kept finding answers, even when Anderson produced moments that would have broken most opponents.
Anderson - bidding to reach the final of the World Championship for the sixth time in his career - struck first, edging a nervy opening set through control rather than fluency.
Van Veen, who eliminated former champion Luke Humphries in the semi-finals, responded immediately in the second, breaking in 10 darts and consolidating with calm authority, his confidence obvious in both shot selection and tempo. From there, the match caught fire.
The fourth set reached a level rarely seen even at this stage. Anderson detonated two immaculate 170 checkouts, the second dragging a stunned Ally Pally to its feet, only for Van Veen to respond with a big fish of his own at the worst possible moment.
Anderson averaged 123 for the set and still lost it, a brutal reflection of the margins at play, but he roared back with a dominant fifth set, piling in maximums and cutting the deficit, before Van Veen steadied once more.
Where Anderson chased moments, Van Veen trusted process. Heavy scoring, clean set-ups and calm corrections on the doubles repeatedly nudged him back in front.
The final sets saw Anderson miss three darts at double 16 at a critical juncture, and Van Veen punished without hesitation. Even when Anderson responded with urgency, Van Veen never lost control of the bigger picture. In the deciding moments, his scoring bursts were cleaner, his finishing more assured.
Van Veen closed the match emphatically, unloading heavy visits to leave double 16 and pinning it cleanly to seal a 6-3 victory and his place in a first World Championship final.
'I'm so happy!'
"To win this kind of game, Gary threw everything at me," Van Veen told Sky Sports.
"His finishing and scoring was great.
"I withstood it. Of course, the crowd was a bit against me, but it's fair play because Gary is such a fantastic human being, such a fantastic darts player. I'm so happy!"
Both players registered three ton-plus finishes and a 170 each in an instant Ally Pally classic.
For Anderson, this was a semi-final exit without regret. He averaged over 105, landed a flurry of maximums and produced finishes of breathtaking quality.
Van Veen, meanwhile, now advances to face Luke Littler in the final, carrying momentum, belief and a game that has already proven it can withstand anything this stage can throw at it.
Semi-final results:
Gian van Veen 6-3 Gary Anderson