Luke Littler was knocked out of the Players Championship 7 by Ross Smith after missing match darts in an agonising last-leg decider.
Teenage sensation Littler had beaten World No 1 Luke Humphries to book his spot in the last-16 but stumbled at the next hurdle after Smith rallied back.
Littler, 17, came into the showdown in red-hot form after winning back-to-back Premier League nights, but his mixed doubling proved his undoing on Monday.
The match went the distance and despite Littler holding the darts, and therefore the advantage, he was unable to clean up on the outer ring, allowing Smith to pounce.
He looked set to progress after taking his score down to 94 but a number of poor darts at a double saw Smith, who was stood on 298, dramatically battle back.
Luke Littler was knocked out of Players Championship 7 after losing to Ross Smith 6-5
The teenage sensation took control of the showdown but squandered several match darts
Littler will hope to win his third consecutive Premier League night in Birmingham this week
Littler initially hit just 46 to leave the door open for his opponent, who piled in a 180.
But even with three more darts in his hand, Littler missed double tops before skewing his attempt at his favoured double 10 by the narrowest of margins.
Smith then stepped back to the oche and took out a 68 checkout with two darts.
Littler will hope to respond to the minor setback at Players Championship 8, which is being held in Leicester tomorrow, and will once again be among the favourites.
He secured his first Players Championship victory back in February, having hit a memorable nine-darter on his way to beating Ryan Searle in the final.
Later this week, Littler will aim to win his third consecutive Premier League night when the action moves to Birmingham. He currently tops the standings.