As their closest rivals failed to win, the league leaders took full advantage as they recorded a 16th win of the campaign thanks to Chitipat Tanklang and David Rochela.
It took only three minutes for Tanklang to open the scoring for the hosts and Rochela added a second four minutes before the hour to secure the points, while Predrag Sikimic was dismissed for the visitors who fell to a fourth successive defeat.
Title rivals Muang Thong United lost ground on Buriram, but may have been satisfied with taking a point after coming from behind to draw 2-2 at Chiangrai United.
Kim Dong-jin put the visitors ahead with 64 minutes gone, but that only served to wake up the opposition as Fernando Ferreira and a Borba own goal turned the contest on its head.
With Dragan Talajic's side facing a third defeat in four matches, they rescued a point with five minutes to play as Mario Gjurovski found the net.
Chonburi were grateful to Thiago Cunha as they grabbed a 1-1 draw with Suphanburi, also hitting back from a goal down to rescue a point and remain in second place.
BEC Tero Sasana were also unable to keep the heat on Buriram or move into an AFC Champions League spot as Osotspa extended their unbeaten run to six games with a goalless draw at the 72-years Anniversary Stadium
At the bottom, Samut Songkhram picked their first league win since June, ending a run of 11 games without a win, as they battered Air Force Central 4-0.
Peemvit Thongnitiroj opened the scoring in the 39th minute before Haiti striker Pascal Millien netted an 18-minute second-half hat-trick to complete the rout.
Unfortunately for Samut, the win did not close the seven-point gap to PTT Rayong after they also picked up three points with a 2-1 victory against Army United.
With the game appearing to be heading for a draw Kirati Keawsombat struck an injury-time winner to move Rayong closer to their rivals.
In a good weekend for the struggling sides there was also a much needed win for Songkhla United as they beat Chainat Hornbill 1-0, but Police United missed the chance to climb out of the bottom five as they were held to a 2-2 draw by TOT.
Meanwhile, Ratchaburi were the highest-placed side to win, moving up to seventh with a comprehensive 3-0 triumph over Bangkok United, and Bangkok Glass beat Sisaket 2-1.
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