Bangkok United moved to the top spot in the Thai League 1 standings after a 2-1 victory over struggling Chiang Rai United on Sunday night.
Suphan Thongsong and Muhsen Al-Ghassani helped the Angels pick up three points and surge one point ahead of defending champions Buriram United, who have two games in hand.
Chiang Rai's only goal was scored by Carlos da Silva.
Bangkok United coach Totchtawan Sripan said: "It was a difficult game for us because we have a loaded calendar and players are exhausted. We had just come back from Hong Kong and did not have much time to rest.
"When we were two goals ahead, it looked like we had the game in hand but then Chiang Rai scored and grew in confidence. We had many chances but lacked accuracy.
"At this stage, it doesn't mean much that we are on top. We will still be taking things on a game-by-game basis."
Meanwhile, hosts Port missed their chance to grab the top spot after settling for a 1-1 draw against Muang Thong United. Felipe Amorim gave Port the early lead, but Felicio Brown equalised for the Kirins in the 23rd minute.
PT Prachuap hammered Uthai Thani FC 3-0 on Sunday night.