Phil Taylor was once again taken to a deciding set but held out to beat Alan Tabern at the PDC World Championship.
Taylor was taken to a decider by Mark Walsh in his previous match
Taylor was trailing 3-2 with Tabern needing 116 to seal the match, but "The Power" hit back with a fine 171 to take the tie into a decider.
The 13-time world champion hit two straight 180s in the 10th leg of the final set to win 4-3 and set up a quarter-final with Wayne Mardle.
Earlier, defending champion Raymond van Barneveld beat Jason Clark 4-1.
Despite suffering from flu, the Dutchman finished off proceedings with his second 11-dart leg of the match to set up a tantalising encounter with Kevin Painter on Friday.
Taylor, who survived scares against both Michael van Gerwen and Mark Walsh, said: "If I go on to win this it will be the hardest world championship I've ever had.
"I used to cruise through games but the players are class now."
Essex's Mardle survived a tense encounter before triumphing 4-3 against Holland's Roland Scholten 4-3.
Alex Roy recorded an upset when he knocked out world number five and 2006 semi-finalist Andy Hamilton.
The world number 27 will meet John Part in the quarter-finals.
Debutant Tony Eccles also produced a remarkable comeback to beat Steve Maish 4-3.
Eccles had been trailing 3-0 but snatched a dramatic win in the deciding set to play Adrian Lewis in the next round.
Former runner-up Mark Dudbridge faces world number three James Wade following a 4-2 win over Ronnie Baxter.