Defending champion and top seed Stephen Maguire of Scotland exited the Pathum Thani 6-red World Championship on the opening day of the tournament on Monday.
Thailand's Nutcharat Wongharuethai, the 2022 world women's snooker champion, also suffered two straight losses on day one and was left with no chance of making it to the knockout phase of the tournament.
Public Health Minister Anutin Charnvirakul chaired the opening ceremony of the 11-million-baht tournament at the 3,600-seat Convention Centre of Thammasat University's Rangsit campus in Pathum Thani.
Maguire was first handed a 5-2 defeat by Chinese ace Ding Junhui and the Scot then went down again to another Chinese opponent later in the afternoon when Zhang Anda beat him by the same scoreline.
The Chinese duo were also responsible for dashing Nutcharat's hopes of making it to the last 16 stage from Group A.
Nutcharat, better known to the local snooker fans as 'Mink Saraburi', did put up a fight but in both games but lost to Zhang 5-2 and then to Ding by the same scoreline.
Noppon Saengkham brightened his prospects for making it to the next phase by beating Englishman Jordan Brown 5-4 in a Group G clash.
Poramin Danjirakul was still in the running for a last 16 round berth from Group C as he followed his 5-2 loss to Hossein Vafaei of Iran with a 5-3 victory over former world champion Ken Doherty of the Republic of Ireland.
Another Thai player Dechawat Poomjaeng was edged 5-4 by Chris Wakelin of England on Monday.
All eyes will be on the much-awaited clash between reigning world champion and No.1 Ronnie O'Sullivan and Thai snooker legend Wattana Phu-Ob-Orm tonight.
The top two players from each of the eight groups will qualify for the last 16 stage with the winner receiving a cash prize of 4.2 million baht and a trophy graciously donated by His Majesty the King.
