The league leaders cruised to a 3-1 win at Sisaket thanks to a Javier Patino double, moving them four points clear at the top of the table.
Patino's strikes before half-time took him to 20 league goals this season and put Buriram United in pole position to win back-to-back titles with just five games remaining.
Meanwhile, Chonburi's 1-0 loss at Army United was their first since June, ending a run of 18 games unbeaten in all competitions. Lee Hyun-jin grabbed the only goal of the game as he pounced in the ninth minute.
The defeat also leaves Chonburi in danger of losing second position as BEC Tero Sasana moved to within three points after victory at Songkhla United.
Having fallen behind to an early Muzafer Ejupi strike, Sasana came back to lead at the break thanks to Ottman Djellilahine's double, but they were pegged back again and needed defender Daiki Iwamasa to secure a 4-3 win and all three points.
Muang Thong United are also in contention for the AFC Champions League qualifying play-offs after Datsakorn Thonglao's 82nd-minute strike saw them beat Air Force Central 1-0.
At the bottom, Samut Songkhram's dismal season continues as they fell to a 25th loss of the campaign, Bangkok United recording a 2-1 win in the capital.
With Songkhla and Air Force Central both losing, the real winners in the bottom five were PTT Rayong as they beat TOT 3-1.
Police United remain in the relegation zone after seeing a 3-1 lead slip away to draw 3-3 with Bangkok Glass.
Osotspa were grateful to Jetsada Puanakunmee as his goal just before half-time gave them a 1-0 win over Suphanburi, while Singhtarua were held to a 2-2 draw by Ratchaburi and Chainat Hornbill fought out a goalless draw with Chiangrai United.
