World Professional Darts Championship
Watch on BBC TV, Interactive and BBC website (UK users only)
Former winner John Walton crashed out of the BDO World Darts Championship in the first round with a 3-0 defeat by Robert Thornton at Frimley Green.
Top seed Mark Webster, who fell at this stage last year, avoided a repeat with a 3-1 win over qualifier Ian Jones.
Number eight seed Gary Robson survived a gripping 37-minute encounter to oust 2002 champion Tony David 3-1.
And fifth seed Tony O'Shea survived a stirring comeback from Shropshire's Steve Farmer to win in his opener 3-2.
Martin Adams begins his title defence on Sunday with a repeat of last year's final against Phill Nixon at the Lakeside Country Club.
John is such a class player but he just didn't get going
Walton, winner in 2001, became the first seed to fall.
But he went into the match arguably as the underdog against the man who won the Winmau World Masters, the BDO's second most prestigious tournament, in November.
Toppling the 12th seed still came as a surprise to Thornton, who now faces O'Shea.
"I really didn't expect to win," the Scot said. "John is such a class player but he just didn't get going.
"He is a hard man to beat but I think winning the World Masters a couple of months ago helped a lot and has given me confidence."
Niels de Ruiter - the 16th seed - followed Walton out of the tournament after going down 3-1 to Glenn Moody, who now plays Webster.
World Cup and Europe Cup singles champion Webster won the first four legs of his match but Jones hit back to make the second set and level proceedings.
Jones twice led in the fourth as Webster missed crucial doubles but he found the double eight when it mattered most to seal victory.
Webster said: "I'm just glad to be through, I wasn't bothered about my average or missing the doubles as long as I got through.
Webster was not the only first-round winner mopping his brow as O'Shea, the 2004 semi-finalist, saw Farmer run off six straight legs to level before he held his nerve in the decider.
O'Shea, from Stockport, said: "That was bad. I just couldn't find my throw. At one point I was standing a good two inches behind the oche."
Meanwhile, Robson pinched a tight fourth set for the win after storming the first two sets only to see David hit back.
He said: "A lot of seeds have fallen in the first round here, it really is the round of death. I'm just glad to be through."
In the women's competition, top seed and five-time runner-up Francis Hoenselaar suffered a surprise 2-0 defeat to Stephanie Smee.