By Gabriel Tan at the Suphachalasai Stadium
After both sides played out a 1-1 first-leg draw in Kuala Lumpur at the weekend, Harimau Malaya were dealt a real blow shortly before the break when Fadhli Shas was sent off for a second bookable offence after a confrontation with Datsakorn Thonglao.
And with the numerical advantage, Thailand went on to grab the win thanks to goals from Teerasil Dangda and Theerathon Bunmathan and, in the process, kept alive their hopes of winning Southeast Asia's premier international tournament for the first time in ten years.
Having grabbed a valuable away goal in last Sunday's first leg at the Bukit Jalil National Stadium, the War Elephants could have been forgiven for approaching the game with a cautious approach.
However, coach Winfried Schafer had declared before the game that his side would go all out for the win, and that certainly proved to be the case as they showed plenty of adventure and enterprise from the opening whistle.
Just four minutes in, they were presented an opening when a lapse in concentration by Aidil Zafuan allowed Jakkapan Pornsai to sneak through in behind the defence, but thankfully for the hosts, Farizal Marlias was quick enough to race out and smother the ball at the winger's feet.
Thirteen minutes later, the hosts had another chance after some lovely interplay down the right between Piyaphon Buntao and Teerasil Dangda saw the former break free and whip in a good cross into the box but from six yards out, Datsakorn was unable to make clean contact with the ball.
By now, Thailand were really starting to cause problems for their opponents with the distribution of Datsakorn and the movement of Teerasil, and a brilliant combination play between the duo really should have handed their side the lead on the half-hour mark.
After leaving Mahalli Jasuli for dead with a ingenious drag-back inside his own half, the War Elephants playmaker proceeded to drill a glorious 40-yard ball in between Fadhli and Aidil and straight into the path of Teerasil, only for him to fire just wide of the far post with only the keeper to beat.
Although they were already firmly in control of the match, the hosts' chances of victory were then given a real boost two minutes before the break when Malaysia were reduced to ten men after referee Lee Min-hu handed Fadhli a second yellow. It initially looked a questionable call, and even though replays did show the defender had gotten into a confrontation with Datsakorn, who also went into the book for his part in the incident, it seemed a very harsh call.
Ten minutes into the second half, Farizal was called into action once more to deny Theerathon, who went straight for goal from a tight angle after the hosts were awarded a freekick on the right.
But right on the hour mark, Thailand finally took the lead after Amar Rohidan's failure to control the ball on the edge of his own box allowed Teerasil to steal in and win possession, before racing through and clinically slotting home.
The 24-year-old could easily have doubled his tally three minutes later when he made his way in behind the Harimau Malaya backline once more, but on this occasion, his touch deserted him at the crucial moment, allowing Farizal to steal the ball at this feet.
Nonetheless, Farizal, who had been doing well up to that point, then undid all his good work in the 65th minute when he parried a well-hit freekick by Jakkapan Pornsai back into the danger area, where Theerathon was on hand to pounce by lashing the rebound into the back of the net to make it 2-0.
The Buriram United left-back, who was been one of the stars of the tournament, then almost turned provider eight minutes later when he swung another of his dangerous set-pieces deliveries into the area, only for Sompong Soleb to send a header back off the crossbar.
With time fast running out, Malaysia desperately needed a goal if they were to have any chance of pulling off a remarkable comeback. That nearly arrived nine minutes from time when Safiq Rahim's cleverly-disguised freekick picked out the unmarked Norshahrul Idlan Talaha at the back post, but Kawin Thamsatchanan was on hand to weigh in with a smart save.
Instead, it was the War Elephants who had the better chances to add to their tally, but both Teerasil and Arthit Sunthornpit failed to get the better of Farizal in clear-cut scoring positions, although those late misses did little to dampen their celebrations when the final whistle eventually blew.
Their progress to the final also means that history will be made at this year's Suzuki Cup as both they and Singapore are gunning to win the title for a record fourth time.
Thailand: Kawin Thamsatchanan, Piyaphon Buntao, Panupong Wongsa, Chonlatit Jantakam, Anucha Kitpongsri, Adul Lahsoh, Phichitphong Choeichiu (Apipoo Suntornpanavej 46'), Datsakorn Thonglao, Jakkapan Pornsai (Sompong Soleb 70'), Theerathon Bunmathan (Arthit Sunthornpit 78'), Teerasil Dangda.
Malaysia: Farizal Marlias, Mahalli Jasuli, Aidil Zafuan, Fadhli Shas, Bunyamin Umar, Azamuddin Akil, Amar Rohidan (Faizal Muhamad 66'), Safiq Rahim, S. Kunanlan (Khyril Muhymeen Zambri 53'), Baddrol Bakhtiar (Safee Sali 72'), Norshahrul Idlan Talaha.