Khon Kaen United became the first team to be relegated from Thai League 1 after suffering a 5-0 hammering at the hands of second-ranked Bangkok United on Sunday.
The Angels were in no mood to show any mercy to the minnows at their home ground and opened their account in the 20th minute when Richairo Zivkovic struck.
The hosts then had a goal from Bassel Jradi after 41 minutes before Khon Kaen defender Diego Landis scored an own goal to let Bangkok United take a 3-0 lead by half-time.
In the second half, Bangkok United remained in command and Luka Adzic scored in the 60th and 85th minutes to complete the rout and condemn Khon Kaen to a year in Thai League 2.
In other games on Sunday night, Lamphun Warriors edged Port 3-2 at home and hosts Nakhon Pathom United lost 4-2 to Muang Thong United.
Meanwhile, Patrik Gustavsson will be out of action for more than six months after suffering an Anterior Cruciate Ligament (ACL) injury in a game on Saturday.
This means the striker will miss the War Elephants' next four matches of the AFC Asian Cup 2027 qualification tournament.
