Judd Trump resumes his quest for a fourth Championship League title, while Mark Allen is also in action at the Morningside Arena on Thursday.
World number one Trump is the most successful player in the tournament’s history; lifting the trophy in 2009, 2014 and 2016.
The Ace has also been a beaten finalist at the round-robin event on two occasions, while reaching the semi-finals a further three times.
A five-time ranking event winner last term, Trump made a strong start to this season by topping Group One in the opening phase with a 100 per cent record.
The 31-year-old will look to build on that as he headlines Group A, which features three other players who were unbeaten during Stage One in Tom Ford, Stuart Carrington and Jimmy Robertson.
The same can be said of three of the competitors in Group B – headed by world number 12 Allen.
The Pistol was runner-up to Marco Fu in the 2010 Championship League, while he also reached the semi-finals two years later.
Allen is aiming for an improvement on the 2020-21 season where, although he won the Champion of Champions, a run to the Gibraltar Open quarter-finals represented his best performance in a ranking event.
The Northern Irishman faces tough competition in an inspired Ricky Walden, who dropped just a single frame while winning all three of his matches in Group Seven, while Fergal O’Brien hit a maximum break in this tournament five years ago.
Peter Lines had to work hard to book his place in Stage Two; the former World Seniors champion lost his opening match against Jak Jones, but recovered by beating Mark Williams 3-0 on the way to topping Group Eight.
The players face each other once in the group with all matches contested over the best of four frames.
Each player will receive three points for a win and one for a draw; the one with the most will top the group and secure a place in Stage Two of the competition.
Championship League Snooker 2021 Schedule
Thursday August 12
Judd Trump v Jimmy Robertson (Group A)
Ricky Walden v Peter Lines (Group B)
Tom Ford v Stuart Carrington (Group A)
Mark Allen v Fergal O’Brien (Group B)
Tom Ford v Jimmy Robertson (Group A)
Mark Allen v Peter Lines (Group B)
Judd Trump v Stuart Carrington (Group A)
Ricky Walden v Fergal O’Brien (Group B)
Stuart Carrington v Jimmy Robertson (Group A)
Mark Allen v Ricky Walden (Group B)
Judd Trump v Tom Ford (Group A)
Peter Lines v Fergal O’Brien (Group B)