Chonburi, who this week announced plans to build a new 20,000-seater stadium, had cancelled out Buriram's lead at the top with a 2-0 win over Muang Thong United on Saturday.
And Buriram had to come from behind to earn a home point against Army - Javi Patino netting the equaliser after Raphael Botti had opened the scoring inside two minutes.
Chonburi's triumph over fourth-placed Muang Thong a day earlier came courtesy of second-half goals from Thiago Cunha and Pipop On-Mo.
Leandro Assumpcao marked his 100th Thai Premier League appearance by rounding off the scoring in Chiangrai United's 3-0 win over Bangkok United.
At the other end of the table, Samut Songkhram's fate was finally sealed by a 2-0 home defeat at the hands of Osotspa.
The strugglers have been cut adrift at the bottom for some time, and the 21-point gap between themselves and safety is now too big a chasm to bridge with six matches left to play.
Air Force Central picked up a valuable point against Singhtarua to aid their own hopes of survival, while fellow strugglers PTT Rayong secured a much-needed 2-0 win against Chainat Hornbill.
In the weekend's other fixtures, Bangkok Glass hammered TOT 6-1, while Suphanburi beat Sisaket 2-0.
