Thai League 1 champions Buriram United completed a double on Sunday night when they beat Nakhon Ratchasima 1-0 after extra time in the FA Cup final.
It was the Thunder Castle's fifth FA Cup victory, having won the event in 2011, 2012, 2013 and 2015. They also lost in the 2018 title match.
Congolese striker Jonathan Bolingi scored the winner against Nakhon Ratchasima after 115 minutes at Thammasat Stadium in Rangsit.
Peeradol Chamratsamee's cross found Maicon who headed the ball into the penalty area and Bolingi found the back of the net from close range.
Nakhon Ratchasima, who were in their first major final, tried to seek an equaliser but failed to break Buriram's defence.
Buriram received five million baht in prize money while the Swat Cats got one million baht.
The triumph was sweeter for Buriram chief Newin Chidchob who has not seen eye to eye with Nakhon Ratchasima chairman Worawi Makudi.
Sunday's win keeps alive the Thunder Castle's hopes for a clean sweep of three major domestic titles.
Buriram are in the League Cup semi-finals and will take on Chiang Rai United tomorrow.
Chonburi meet Prachuap in the other semi-final.
The Thunder Castle have won all three major domestic trophies in the same season three times in 2013, 2013 and 2015.
They have lifted the League Cup five times, the last in 2016.