Jackson was defending his title at Potters in Norfolk
Reigning champion and top seed Billy Jackson has been knocked out of the World Indoor Singles by Canadian outsider Hirendra Bhartu in Norfolk.
Englishman Jackson, who lost in the pairs final on Sunday, was beaten 7-7 8-8 2-1 in the second round.
Scottish-born Andy Thomson, who won the pairs with Ian Bond and seeded eight, also lost, to fellow Englishman and qualifier Robert Paxton by 7-6 6-5.
But Scotland's Paul Foster (4) and David Gourlay (6) both won.
Foster defeated Welshman Richard Morgan 2-8 6-4 2-1, while Gourlay, who lost the pairs final with Jackson, beat Scottish qualifier Gary Hutchison 10-6 9-1.
Lincolnshire 39-year-old Jackson admitted that the pressure of defending his title had got to him against the world number 21.
"It's a funny pressure, defending your title," he said. "I've never experienced it before.
"However, I think I put most of the pressure on myself. But he played some very good bowls."
Jackson's exit continued a trend of surprise results at Potters.
Welsh qualifier Jarrad Breen, aged just 17, knocked out third seed Mark Royal, of England, on Tuesday.
Australian qualifer Ben Twist defeated Englishman Bond, seeded 12, while compatriot Steve Glasson put paid to the hopes of English ninth seed Mervyn King.
Unseeded Nick Brett accounted for 14th seed and fellow Englishman Simon Skelton.