A spirited Thailand, who won the first leg 2-0 in Bangkok on Wednesday (December 17), rallied from 3-0 down at the packed Bukit Jalil stadium to claim 4-3 aggregate win.
It is Thailand's fourth crown at the biennial championship, matching Singapore's record. The Thais previously won in 1996, 2000, and 2002.
With the win, Thailand coach Kiatisak Senamuang became the first man to win the Asuean title both as a player and a coach.
The 41-year-old won the title three times as a player. He was a member of the Thai team that beat Malaysia in the final of the inaugural edition in 1996.
The team will receive about B25 million in bonuses and prize money.
At Bukit Jalil, which was packed to its 90,000 capacity with Malaysian Prime Minister Najib Razak a in attendance, the hosts got off to a fast start and took a 1-0 lead on the night just after six minutes in a controversial manner.
Iranian referee Faghani Alireza awarded Malaysia a penalty after Thailand defender Suttinon Phukhom was adjudge to have fouled Malaysia striker Norshahrul Talaha.
Thailand's appeal was turned down and Safiq bin Rahim made no mistake from the spot.
Perhaps unsettled by the early goal, Thailand failed to find their rhythm as the Tigers piled pressure on the War Elephants.
Kroekrit Thaweekarn came close to scoring an equaliser just before half-time. But moments later, Thailand goalkeeper Kawin Thammasatchanan missed a cross allowing Indra Putra to head the ball home to make it 2-0 on the night and 2-2 on aggregate.
Thailand regrouped in the second half but it was Malaysia who went in front after 58 minutes when Safiq Rahim's 25-yard free-kick beat Kawin. Malaysia would have lifted the trophy with that scoreline.
However, the Thaids staged a fightback and threw everything at Malaysia.
Their attempted were rewarded in the 82nd minute when goalkeeper Farizal Marlias could only block a Sarach Yooyen free-kick and Charyl Chappuis calmly served the loose ball into the back of the net. Chanathip Songkrasin put the tie beyond any doubt with a strike four minuted from time.
Chanathip was named the best player of the tournament. The champions got US$200,000 and the runners-up US$75,000. Bangkok Post