Thailand reached the AFF Suzuki Cup final after beating the Philippines 3-0 in the semi-final second leg last night for a 3-0 aggregate win.
The fans prior to the start of the match.
Kroekrit Thaweekarn was on target twice after 57 and 87 minutes after Chanathip 'Messi J' Songkrasin opened the scoring in the sixth minute at a packed Rajamangala National Stadium.
Coach Kiatisak Senamuang's men will meet Vietnam or Malaysia in the two-legged final.
The War Elephants will be at home on Dec 17 and away on Dec 20 as they are chasing a record-equalling fourth title at the Asean championship.
Vietnam, who won 2-1 in Kuala Lumpur in the first leg, host Malaysia today for a place in the final.
Thailand have won the Asean title three times, with Kiatisak a member of those three teams.
The Thais last lifted the trophy in 2002 and lost to Singapore in the 2012 final as the Lions claimed a record fourth crown.
Chanathip Songkrasin celebrates his goal. photos by Pattarapong Chatpattarasill
"Our mission is not yet complete as we will have to play in the final," Kiatisak said after last night's match.
"Our players knew what to do to win today. We do not care whether we face Vietnam or Malaysia in the final. We are ready to face anyone. Our target is to bring the trophy back to the country."
The Philippines coach Thomas Dooley said: "Thailand deserved to win the match. Our defenders made some mistakes in this match and after the first goal we tried to improve but we could not do it."
In the first leg in Manila on Saturday which ended scoreless, the Philippines played well and were dominant in the final 20 minutes after Thailand striker Adisak Kraisorn was sent off.
But it was a different story at Rajamangala last night as the Thais dominated for long periods and could have won by a bigger margin.
Kiatisak was without his regular strikers Kirati Kaewsombut, who is injured, and Adisak, who was suspended.
He used midfielder Chanathip as a lone striker against the Philippines and the move paid off after just six minutes when he gave Thailand the lead with a close-range strike.
Kroekrit beat an offside trap to make it 2-0 after 57 minutes and completed the rout three minutes from time.
The Philippines' Martin Stuble was dismissed after 82 minutes after receiving his second yellow card.
In Hanoi, Vietnamese authorities have promised to beef up security and protect visiting Malaysian fans in today's semi-final.
Officials said they would deploy thousands of police and separate rival supporters to avoid a repeat of the violent clashes that marred Sunday's first leg in Malaysia.
"Even though the number of Malaysia fans is not too many, they will get seats in designated areas," Can Van Nghia, the director of the national stadium, said.
"Malaysian fans will be very safe at My Dinh Stadium."
The move to increase security followed ugly scenes in the first leg, won 2-1 by Vietnam, with five people arrested after fighting broke out in the stands.
Malaysian Sports Minister Khairy Jamaluddin issued an apology to Vietnam's supporters and spoke with Vietnam's ambassador to Malaysia. Bangkok Post/Reuters