Supachai Chaided scored twice as Buriram United hammered hosts Chiangmai United 4-1 to regain the Thai League 1 lead on Sunday night.
After a scoreless first half, the Thunder Castle caught fire with goals from Kenya's Ayub Masika (52), Supachai (55 and 60) and Suphanat Mueanta (68).
The bottom side got a consolation from Poolsak Masuk late on.
After 16 games, Buriram have 35 points, two ahead of Bangkok United, whose game against Samut Prakan was postponed due to Covid-19.
Buriram did not play last week because of coronavirus-related issues.
It was a winning start for Japanese coach Masatada Ishii who joined Buriram from Samut Prakan last month.
"The first half was not smooth for us," he said.
"But after we got the first goal, our players looked relaxed and played very well. We are happy to start [the second half of the season] with a win."
Meanwhile, Thai League 1 could become chaotic after Muang Thong United announced yesterday their player Sarador Mirzaev of Uzbekistan tested positive for Covid-19.
The Kirins said the test result was only known after their match against Pathum United on Sunday.
The midfielder is now in isolation as Muang Thong offered apologies to all involved parties.
Several matches have been postponed because of Covid-19 since the second leg of the season started earlier this month.