Two-time champions Gary Anderson and Michael van Gerwen will meet in the PDC World Championship semi-finals after winning their last eight ties.
Anderson averaged 103.03 and hit 12 maximums as he powered to a 5-2 victory over Dave Chisnall at Alexandra Palace.
Number one seed Van Gerwen was less convincing but beat Ryan Joyce 5-1.
Nathan Aspinall will play Michael Smith in the other semi-final after comfortable 5-1 wins over Brendan Dolan and Luke Humphries respectively.
Bad back does not stop Anderson
Number four seed Anderson only lost one leg on the way to a 2-0 lead, before taking the third set on a deciding leg.
The Scot missed a double nine to go 4-0 up and Chisnall, ranked 12th, capitalised to win the fourth set.
But a 130 finish saw Anderson take the fifth set and, though his rival took the sixth, he closed out the win.
Anderson, champion in 2015 and 2016, hit 12 maximums and said he won despite having a sore back that had resulted in a trip to the chiropractor on Friday.
I was fighting against myself - Van Gerwen
Van Gerwen started off impressively as he went 2-0 up but was not at his fluent best as Joyce took the third set.
World number 74 Joyce had the darts at 2-1 up in the fourth set only for Van Gerwen to break his throw and go on to take a 3-1 lead.
The Dutchman then secured the next two sets for victory, averaging 101.12, but said that after a strong start he "played terrible to be fair".
He added: "I was fighting against myself as I wanted to show everyone what I could do.
"A 5-1 win, I can't complain."
Aspinall averaged just under 100 in his win over Dolan.
"Two weeks ago I was making my debut at the Ally Pally, now I'm a world semi finalist," said Aspinall on Twitter.
"Dreams do come true. With the right support and dedication you can achieve anything and I'm still not finished."
Smith eased to a 5-1 victory over Luke Humphries, who had knocked out defending champion Rob Cross.
Humphries, ranked 90th, had to come back from 2-0 down to beat Cross but could not repeat the trick this time around, although he did complete a 170 checkout in the match.
Tenth seed Smith was too strong for his rival as he averaged 103 and hit eight maximums.