By ESPNSTAR.com staff
The Twin Qilins, who wrapped up the title a couple of weeks ago, fell behind in the 12th minute when Nattaporn Panrit opened the scoring for BEC Tero.
However, they hit back five minutes after the half-hour mark through Adnan Barakat, before Teerasil Dangda fired them ahead a minute before the break with what could be his final goal for the club.
Fire Dragons striker Cleiton Silva then netted on the hour mark to salvage a share of the spoils for his side, although the game was soured in injury-time when both Rangsan Viwatchaichok and Mario Gjurovski were issued their marching orders.
Second-placed Chonburi ended their season on a high as a first-half brace from Thiago Cunha handed them a 2-1 win at Thai Port, who pulled one back on the stroke of halftime through Steven Robb.
Last season's champions Buriram United, who are still challenging for both the FA Cup and League Cup, fell to a 2-1 away defeat to Chiangrai United.
Suriya Domtaisong gave the visitors the lead after 16 minutes when he found space inside the area and clipped a shot just inside the bottom corner, but Chiangrai hit back 11 minutes later when Uilian Souza netted from the spot.
Seven minutes from time, Wasan Natasan pounced on a loose ball and fired home from close range to hand the Fighting Beetles all three points, which was enough to seal a top-half finish.
Bangkok Glass, who have had an inconsistent season, had to settle for 8th place despite a convincing 5-1 win over nine-man Wuachon United.
Anawin Jujeen broke the deadlock for the Glass Rabbits after just five minutes, but the hosts hit back two minutes later through Supasak Gaigaew.
Nonetheless, Wuachon were reduced to ten men shortly after the break and two minutes later Hironori Saruta restored the visitors' lead from the spot, before Teeratep Winothai made it 3-1 eight minutes later.
Five minutes after the hour mark, Peerapong Pichitchotirat added a fourth and shortly after Wuachon had another man sent off in the 74th minute, Rafael Souza weighed in with one of his own to cap off a wonderful night for Glass.
High-flying Samut Songkhram finished one place above them after second-half goals from Bireme Diouf and Porawat Siriwatanagorn handed them a 2-0 home win over Pattaya United, while Michael Byrne scored the only goal of the game in Chainat's 1-0 triumph over Army United.
Bottom side TTM Chiangmai were handed a 20th and final defeat of the campaign as they were beaten 2-0 by Police United courtesy of goals from Leandro dos Santos and Lee Han-guk.
Elsewhere, relegated BBCU fell to a 1-0 defeat at Esan United, while Osotspa Saraburi, who had sewn up a top-five finish prior to Sunday's fixtures, beat TOT 3-1.
Sunday's Thai Premier League Results
BEC Tero Sasana 2-2 Muangthong United
Chainat 1-0 Army United
Chiangrai United 2-1 Buriram United
Esan United 1-0 BBCU
Samut Songkhram 2-0 Pattaya United
Thai Port 1-2 Chonburi
TOT 1-3 Osotspa Saraburi
TTM Chiangmai 0-2 Police United
Wuachon United 1-5 Bangkok Glass