Gary Anderson knows he will need an improved performance in his fourth round match with Rob Cross on Thursday night after scraping past Ian White in round three.
Wednesday saw Anderson fight back from 3-0 down to beat White 4-3 and keep his hopes of a third World Championship title alive.
The 51-year-old will take on in-form Cross for a spot in the quarter-finals, a player Anderson has lost just once against in seven TV meetings.
"It was absolutely atrocious to be honest but I got there in the end," Anderson admitted.
"Once I got it back to 3-3 I fancied myself to win it, I could see Ian was starting to struggle.
"The darts are going in at a lovely angle in the practice room but they're just not going in the same up there for some reason.
"I will need to up a few levels against Rob but I've got a really good record against him.
"But the thing with having good record against people is they are even more determined and at some point they will beat you.
"I've played here for 13 years now and I've reached the final six times so I think I've done alright.
"It would be nice to get there again but I will need to play a lot better."
Anderson v Cross is one of three fourth round ties taking place on Thursday's evening session.
The World Championship is being broadcast live on Sky Sports in the UK, through the PDC's worldwide broadcast partners including DAZN and RTL7, and on PDCTV (excluding UK and Netherlands based subscribers).
2021/22 William Hill World Darts Championship
Schedule of Play
Thursday December 30
Evening Session (1900 GMT)
3x Fourth Round
James Wade v Martijn Kleermaker
Gary Anderson v Rob Cross
Peter Wright v Ryan Searle
Best of seven sets
There will be a tie-break rule employed in all matches; where a deciding set must be won by two clear legs. If the score in the final set reaches 5-5 then a sudden-death leg will be played.
There would be no throw for the bull in any sudden-death legs.