Ross Smith produced the shock of the tournament as he defeated world number one Price 11-8 in a high-quality contest.
Smith, who hit a 161 checkout in the match, will now face Wade in the last eight on Thursday.
Price took an early 3-1 lead but Smith fought back to level at 4-4 and then won four of the next five legs to seal victory.
The Welshman averaged 102.55 but it wasn’t enough to stop Smith, who averaged 99.98 and hit 11 maximums.
It was a sensational performance from Smith who will now be looking to continue his impressive form in the quarter-finals.
With Aspinall and Price now out of the tournament, the World Matchplay is wide open and the remaining players will be looking to capitalise on the opportunity to claim the title.
It promises to be an exciting conclusion to the tournament as the remaining players battle it out for the prestigious trophy.
We played together in the same youth team, so to play him on such a big stage was really tough, said Humphries.
It wasn’t an easy game. Stephen played really well but I’m just happy to get through. I’ve got a lot of respect for him.