Taku Ito scored the winning goal as hosts Nakhon Pathom United picked up three points after a 2-1 victory in their Thai League 1 game against former champions Chiang Rai United on Saturday night.
Chaiyaphon Otton put the home team ahead in the ninth minute but the Beetles equalised after 33 minutes through Sittichok Kannoo.
Japanese Ito helped Nakhon Pathom secure three points from the game, finding the net in the 83rd minute.
Ito said: "I am very happy to have helped my team get back to their winning ways.
"We will keep on fighting in the second leg because we want to survive in Thai League 1."
VAR use at Asean meet
The Asean Football Federation (AFF) has confirmed the use of the Video Assistant Referee or VAR during the Asean Mitsubishi Electric Cup 2024, which started Sunday.
It is the first time that VAR is being used in the Asean championship to "upgrade the standard of refereeing" in the region's biggest tournament.