Michael White and Alfie Burden moved a step closer to reclaiming their places on the World Snooker Tour at Q School event one, but former world number two Tony Knowles suffered a setback in his bid to rejoin the sport's elite.
Former world number 15 White will face veteran cueman Peter Lines in round four of qualifying on Monday afternoon at Ponds Forge in Sheffield with both players having compiled two centuries apiece in winning their first three matches.
They need three more victories to claim one of the four tour cards up for grabs on Tuesday when event one concludes.
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Welshman White has lifted the Indian Open, Shoot Out and Paul Hunter Classic, but dropped off the main tour last year after a slump in form. He is among the favourites to complete his comeback and enjoyed a break of 93 in a 4-1 win over Ben Fortey with 2018 Paul Hunter Classic semi-finalist Lines a 4-2 winner against Riley Parsons.
Three-times World Championship semi-finalist Knowles is bidding to rejoin the WST ranks at the age of 65.
He looked poised to progress to round four as knocks of 69 and 54 helped him ease 3-1 clear of Raymond Fry only for the Northern Irishman to recover with runs of 110 and 67 helping him reel off three straight frames for a 4-3 success.

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Bolton favourite Knowles will return for the start of event two on Wednesday as he continues his quest to return to the main tour after a 20-year absence.
Former world amateur champion Burden – who has reversed his decision to quit the sport a year ago – completed 4-1 victory over Ryan Thomerson boosted by breaks of 55, 56 and 66 in round two to set up a meeting with former German Masters semi-finalist Duane Jones in round three.
“Last year I said I had retired and I had no intention of coming back,” said Burden. “I could have played in a few ranking events last season as a top-up amateur, but pride in my own performance stopped me, I didn’t want to just turn up having not played for months."
World seniors champion David Lilley despatched Paul Davison 4-0 in round three with runs of 50, 66 and 60 to secure a meeting with Paul Davies.

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Event one finishes on Tuesday with round five and four quarter-finals settling matters ahead of event two and event three being contested with 14 tour cards up for grabs before Q School concludes on Sunday 13 June.
The four semi-finalists in each event earn a two-year tour card for the 2021/22 and 2022/23 seasons with the next two highest players on the Q School Order of Merit also securing a card.
All matches are contested over the best of seven frames.
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