Littler had been imperious in Milton Keynes but Clayton had also impressed and broke the tournament record with his 112.77 average in the first round.
Clayton still averaged over a ton in the quarters, even though his 103.96 and eight 180s was bettered by Littler’s 108.5 and nine maximums – but the Welshman was superior on the doubles.
‘The Ferret’ had a 60% checkout percentage to Littler’s 35% – and had three ton-plus finishes including a 128 and 138 when taking the opening set.
Littler, who turned 18 in January, went off the boil as Clayton took the next two sets to lead 3-1, and even though the world champion got back to 3-2 Clayton kept his nerve to book his spot in the semis.
“The stage likes me,” Clayton told ITV4. “Obviously Luke didn’t play his A game, but it’s a battle and I got over the line.
“He’s a cracking guy and great darts player, with a great future. He’s given me a big lesson the last two games I played him, so I got one back.
“It went my way and it was my day.”
