World number one Colin Lloyd was dumped out of the Budweiser UK Open at the fifth-round stage by Chris Mason.
The players shared the first eight legs before Mason won five in a row to lead 9-4. He then held his nerve, despite a fightback, for a memorable 11-7 win.
World champion Phil Taylor beat Welsh qualifier Steve Alker 11-1 to reach the last 16 while another darts legend, John Lowe, beat Andy Belton 11-4.
Colin Monk lost 11-0 to Adrian Lewis and James Wade beat Bob Anderson 11-9.
"I don't think I've ever finished better, and I was very consistent," said Mason.
"I had a mid-game wobble but kept convincing myself that I could win and I fell over the line.
"I've been around for a long time and maybe in the next 12 months I can take a major title.
"I've re-applied myself and been a lot more disciplined and things like that are starting to make a difference for me - I used to choke because I wanted to win so much."