Nattawut Sombatyotha's late double helped Thailand ease to a 3-0 victory over Cambodia in the Southeast Asian (SEA) Games in Malaysia on Sunday night.
The Ratchaburi striker came off the bench to net a brace after Picha U-Tra had given the Thais a first-half lead.
Both sides played with 10 men in the second half after Chaiyawat Buran and Sok Samnang were red-carded for violent conduct just before the half-time whistle.
After a slow start, the Thais burst into life in the 15th minute when Chaiyawat headed wide from Picha's cross when he should have hit the target. A minute later, Chaiyawat put Picha through on goal, but the winger's shot was well saved by Un Serei Rath.
The Cambodian keeper was then at the heart of the action for the wrong reasons when his error handed the War Elephants the lead in the 35th minute. Under pressure in his own box, Chreng Polroth nudged the ball back to Serei Rath, but the keeper's attempt to clear was charged down by Picha, who tapped the ball into an empty net.
Seri Rath redeeemed himself minutes later when his quick reactions denied Chenrop Sampahodi as the Thais pressed for a second.
The first half had a dramatic ending as Chaiyawat received a red card for kicking out at Hoy Phallin in retaliation, sparking an angry reaction from the Cambodian players. Samnang was also sent off for stamping on Chaiyawat in the brawl that followed.
The second half started at 10 versus 10 and the Cambodians had a chance to level in the 55th minute. Noun Borey twisted and turned past Worawut Namvech before firing in a shot that Nont Muangam pushed out.
This seemed to prompt more urgency from Thailand, and they responded with a dipping shot from substitute Sasalak Haiprakhon that just cleared the bar.
Worawut should have wrapped things up in the 70th minute but headed over from Sasalak's free kick.
But Thailand were given the perfect opportunity to add a second goal in the 76th minute when they were awarded a penalty after Soeuy Visal brought down Picha. Nattawut Sombatyotha confidently fired home from the spot to put the game beyond Cambodia.
And Thailand added a third with two minutes remaining when Nattawut took Suriya Singmui's pass in his stride and volleyed home from 16 yards,
In other Group B action, Vietnam maintained their 100 per cent record with a 4-0 victory over Philippines. The group leaders took the lead through Cong Phuong in the 38th minute, and quickly added two more from Vu Van Tranh and Nguyen Van Toan before Ho Tuan Tai wrapped things up in the 89th minute.
Indonesia stayed in contention for a semi-final spot with a 1-0 win over Timor-Leste in a bad-tempered match. Marinus Wanewar's first-half header sealed three points for Luis Milla's side, but the game ended in an ugly brawl, with Pilipe Oliveira sent off for kicking Evan Dimas.
Vietnam face Indonesia on Tuesday in a match that will have a huge bearing on the outcome of the group.