Alfie Burden says it would be “ridiculous” for John Higgins to retire after he knocked the four-time world champion out of the Scottish Open.
Englishman Burden beat Higgins 4-2 in the last 16 at the Emirates Arena in Glasgow on Thursday.
He now faces Northern Ireland’s Mark Allen in the quarter-finals.
“It feels amazing because John’s probably the best player alongside Ronnie O’Sullivan to ever have played the game,” Burden told BBC Scotland.
“I just kept fighting like I’ve done all week.”
Burden had come from 3-0 down to win 4-3 in the two previous rounds, and almost lost his place on the tour before the start of this season.
He and Higgins are long-time friends and Burden is aware of the retirement thoughts the Scot’s mind has been entertaining.
“I spoke to John the other day,” said Burden. “I told him what I thought and, to cut a long story short, I did say he’d be winning tournaments for another seven or eight years because he’s that good.
“So I think it’s ridiculous if he ever considers retiring – I don’t think he will.”
Higgins said after this defeat that his head is in a “better” place than it was a few days ago, and insisted he would make no rash decisions about his future.
“I’ll just have a good Christmas and see what happens at the Masters and tournaments after that.” he told BBC Scotland.
“I played a bit better this week than I had been doing, but then it was back to pretty bad there.”
Allen, who was beaten in the UK Championship final by Ronnie O’Sullivan on Sunday, beat Scotland’s Graeme Dott 4-2.
Former world champion Shaun Murphy and compatriots Stuart Carrington and Sam Baird all edged through 4-3, Wales Ryan Day beat Ding Junhui 4-2, and Daniel Wells whitewashed Matthew Stevens.