Littler averaged 102.67 to Pietreczko’s 90.41 and threw six maximum 180s to his opponent’s two.

“I am never happy when I am losing. At 3-2 down, I then got it back to 5-5 and I just had to kick on there,” Littler said.

“I managed to get the job done. I was not the best on my doubles tonight, but I can sharpen up on them again tomorrow afternoon.”

Littler reached the last 16 earlier on Saturday with a 6-3 win against Englishman Ross Smith.

Wales’ Gerwyn Price beat Poland’s Sebastian Bialecki 6-1 and German Martin Schindler 10-6 to move into the quarter-finals.

He will play Northern Ireland’s Daryl Gurney, while England’s Nathan Aspinall meets Northern Ireland’s Josh Rock and Englishman James Wade faces the Netherlands’ Jermaine Wattimena.