In front of a large crowd, in a ring specially built on Patong Beach, Petchbangbon pummeled Alhabsyi into submission after just two minutes of the first round.
Petchbangbon won the vacant title last year in a bout with Wandee Singwangcha from Koh Samui, and successfully defended it in February this year in a fight with Richard Garcia of the Philippines.
He has won all of his past 10 fights. His challenger, Alwi had not done so well – his record in the past 10 fights was three wins, one draw and six defeats.
The match was the highlight of a boxing fiesta on the beach, consisting of five boxing matches and 10 Muay Thai fights between noon and 8.30pm. All the matches were broadcast live on Thai TV Channel 5.