Thai Premier League leaders Muang Thong United were held to a 1-1 draw at Bangkok United on Sunday, while Buriram United and Chonburi won.
Muang Thong entered the match in poor form, having lost four of their last six matches in all competitions.
And although they still lead the division by two points, they were far from their best in a disappointing draw against their struggling opponents, who sit fourth from bottom in the table.
The hosts took the lead on the half-hour mark as Sompong Soleb netted and they carried this advantage into the break.
However, Ivorian Dagno Siaka levelled seven minutes after half-time for Muang Thong United, with both sides eventually forced to share the spoils.
Meanwhile, second-placed Buriram kept the pressure on their title rivals with a 2-1 win at Samut Songkhram.
A Suksayam Chanmaneewech own goal after 14 minutes gave the winners the lead and it was an advantage they held for most of the match.
Ghanaian Gilbert Koomson bagged the equaliser in the 72nd minute for Samut Songkhram but their opponents had enough time to claim a late, dramatic winner.
Carmelo was the scorer with just three minutes to play as Buriram's excellent form continued.
Chonburi are level on points with Buriram after a convincing 3-1 home win over Bangkok Glass.
The winners scored all three of their goals inside eight first-half minutes, with Kitpongsri Anucha getting the first on 28 minutes.
Thiago Cunha then fired a quick double and although Praweenwat Boonyong produced a response before half-time, it was merely a consolation.
Other results on Sunday saw Seydou Kone's stoppage time equaliser give Songkhla United a 1-1 draw at Osotspa while Police United and Chiangrai United played out a goalless draw.