Unbeaten BG Pathum United kept second-ranked Port at more than an arm's length as the two sides recorded victories on Saturday night when Buriram United made a big leap up the Thai League 1 table.
Pathum, who saw Thailand striker Teerasil Dangda strike on his debut for the club, were 2-0 winners over hosts Police Tero as the top flight returned to full action behind closed doors after a month-long shutdown forced by a fresh coronavirus outbreak in the country.
It was the first time that Teerasil joined former Buriram star Diogo Luis Santo as strike partner and they both impressed in their first league games for Pathum, with Teerasil putting them on course in the 16th minute.
Chatree Chimtalay netted their second during the final 10 minutes of the game.
Port looked set to drop points against 10th-ranked Sukhothai in their last night's home game before Kevin Deeromram set up Yannick Boli to secure a 1-0 win in the last minute of injury time.
Chiang Rai United claimed a 3-1 away victory over relegation-threatened Trat.
Earlier, Buriram routed 10-man Ratchaburi 3-0 in a home game to leapfrog their opponents and defending champions Chiang Rai into third place in the league standings on goal difference.
The first goal for the hosts came in the 19th minute when Brazilian striker Samuel Rosa guided the ball into the net from close range.
Ratchaburi's hopes of pulling off a rallying win were dented in the 39th minute when goalkeeper Ukrit Wongmeema used his hand outside the box to clear the ball, trying to thwart a counter-attack by Supachai Chaided, and was sent off following a VAR replay.
In the second half, Ratchaburi continued their efforts for the leveller and saw a Steeven Langil shot miss the target and Javier Patino hit the bar.
Buriram widened the margin with Myanmar striker Aung Thu scoring in the 64th minute.
After Siwarak Tedsungnoen denied Ratchaburi skipper Philip Roller from the penalty spot, Rattanakorn Maikami put the visitors' hopes of a comeback to rest with a free-kick 15 minutes from time.
Four more matches are scheduled to be played on Sunday.