By ESPNSTAR.com staff
Wichaya Dechmitr put the Fire Dragons ahead after 19 minutes, and although Chiangmai equalised through Leonardo Ferreira da Silva in the 39th minute, Cleiton Silva netted four minutes later to ensure his side went in ahead at the break.
Four minutes into the second half, BEC Tero added a third through Rangsan Viwatchaichok, before edging further ahead shortly after when Silva added his second.
From then on, there was only ever going to be one winner and Amorn Thammanarm capped off a fine day at the office for the hosts when he added a hat-trick in the final half hour to add gloss to the result.
Muangthong United's charge to the title hit a slight blip as they were held to a 1-1 draw at TOT, in a feisty encounter that saw both sides reduced to ten men.
Prakit Deeprom broke the deadlock for the visitors in the 74th minute but Dagno Siaka equalised two minutes later to earn the Twin Qilins a share of the spoils, which was enough to see them edge 14 points clear at the league summit.
Second-placed Chonburi almost have no chance of catching Muangthong after falling to a 2-1 loss at high-flying Esan United, who moved up to fifth following Wednesday's triumph.
Arthit Sunthornpit looked to have forced a draw for the Sharks when he scored in the 86th minute to cancel out Wuttichai Tathong's 27th-minute opener, but Esan were not to be denied and eventually grabbed all three points when Chayene Santos grabbed a dramatic winner in injury-time.
Police United's handed their hopes of avoiding relegation a further boost after defeating free-falling Bangkok Glass, who have not won in their last eight league outings.
Tana Chanabut fired the Silver Shields ahead in the 16th minute, and while that was cancelled out six minutes after the hour mark by Peerapong Pichitchotirat, the hosts edged ahead again five minutes later through a Surachart Sareepim strike.
The Glass Rabbits were then reduced to ten men when Peerapong turned from hero to villain by receiving his marching orders, and Police made full use of their numerical advantage by adding another through Tana.
In the first game since their hopes of retaining the title were ended, Buriram United were held to a 0-0 draw at home to Samut Songkhram, while Ivorian midfielder Anthony Moura-Komenan scored the only goal of the game in the 61st minute to hand Osotspa Saraburi a 1-0 triumph over Army United.
Olof Hviden-Watson netted twice to help relegation-threatened Thai Port beat Chiangrai United, while second-from-bottom BBCU were held to a 1-1 draw at home to Wuachon United, with Sarawut Janthapan scoring in the 77th minute to cancel out Junior Aparecido's opener for the hosts.
Finally, Chainat's bid to avoid the drop was given a boost after they came from behind to record a 4-2 home win over Pattaya United.
After Phuwadon Suwannachat opened the scoring in the 26th minute, Pattaya hit back with goals from Gabriel Obatola and Kengne Ludovick to claim a 2-1 lead at the 55th-minute mark.
Nonetheless, the Hornbills refused to give in and duly equalised through Michael Byrne, before going on to grab all three points courtesy of goals from Somjed Satthaboot and Kendall Jagdeosingh in the final nine minutes.
Wednesday's Thai Premier League Results
Thai Port 2-0 Chiangrai United
BBCU 1-1 Wuachon United
Chainat 4-2 Pattaya United
Esan United 2-1 Chonburi
Osotspa Saraburi 1-0 Army United
BEC Tero Sasana 7-1 TTM Chiangmai
Buriram United 0-0 Samut Songkhram
Police United 3-1 Bangkok Glass
TOT 1-1 Muangthong United