ImagoSelby then defeated Andy Lee 5-1 in the late-afternoon session with an equally assured and confident display, ensuring his progress from Group A of the round-robin stage.
The 2010 champion - the tournament was not held in the 2011-12 season - has now won all three of his matches in Thailand by the same scoreline.
Judd Trump, the world number two, sealed an even more convincing win as he thrashed Nick Jennings 5-0 in their Group B encounter. He has now won two of his three matches so far.
Veterans Jimmy White and Steve Davis secured fine wins after sluggish starts.
White had lost both of his previous Group F matches, but he responded in fine fashion to overcome Stuart Bingham 5-4 in an impressive win.
It was a nervy victory for White, who desperately needed to hit back after a hugely disappointing start to the group stages. He followed it up with a 5-2 win over Passakorn Suwannawat later in the day.
Davis had no problems in whitewashing Andrew Higginson 5-0 in their Group E match after he too suffered a poor start to the competition.
It was an emphatic win for Davis, who was unwavering in his approach and Higginson was afforded no opportunities to compete.
However, Davis lost his later match against Shaun Murphy as the higher-ranked player ran out a 5-1 winner.
Day two round-robin results:
Morning session:
Group E Thepchaiya Un-Nooh 4-5 Pankaj Advani
Group D Mark Davis 3-5 Hossein Ayouri
Group H Marco Fu 5-3 Panompai Powises
Group G Matthew Stevens 3-5 Noppon Saengkham
Group E Andrew Higginson 0-5 Steve Davis
Group A Dominic Dale 3-5 Andy Lee
Group B Rodney Goggins 5-4 Issara Kachaiwong
Group G Ricky Walden 5-0 Krzysztof Wrobel
Lunchtime session:
Group H Graeme Dott 5-3 Zhang Anda
Group B Judd Trump 5-0 Nick Jennings
Group A Mark Selby 5-1 Joe Perry
Group C Mark Williams 5-4 Aditya Mehta
Group D Mohammed Ibrahim 1-5 Darren Morgan
Group H Martin Gould 4-5 Lee Walker
Group F Stuart Bingham 4-5 Jimmy White
Group F Stephen Lee 5-3 Saleh Mohammad
Mid-afternoon session:
Group G Matthew Stevens 5-2 Krzysztof Wrobel
Group C Ken Doherty 2-5 Thanawat Tirapongpaiboon
Group G Ricky Walden 5-2 Tom Ford
Group A Shachar Ruberg 1-5 Dechawat Poomjaeng
Group C Peter Ebdon 5-2 Li Hang
Group E Andrew Higginson 5-2 Pankaj Advani
Group G Marcus Campbell 4-5 Noppon Saengkham
Group B Barry Hawkins 5-1 Mohamed Khairy
Late afternoon session:
Group F Jimmy White 5-2 Passakorn Suwannawat
Group E Ben Nunan 2-5 Thepchaiya Un-Nooh
Group D Darren Morgan 3-5 James Wattana
Group H Zhang Anda 3-5 Marco Fu
Group H Graeme Dott 3-5 Lee Walker
Group F Stephen Lee 2-5 Stuart Bingham
Group A Mark Selby 5-1 Andy Lee
Group F Ben Judge 4-5 Saleh Mohammad
Evening session:
Group C Mark Williams 5-1 Li Hang
Group E Shaun Murphy 5-1 Steve Davis
Group A Dominic Dale 3-5 Dechawat Poomjaeng
Group C Peter Ebdon 3-5 Thanawat Tirapongpaiboon
Group B Barry Hawkins 4-5 Issara Kachaiwong
Group D Stephen Maguire 5-1 Mohammed Ibrahim
Group A Joe Perry 5-4 Shachar Ruberg
Group C Aditya Mehta 5-2 Ken Doherty
