Pre-tournament favourites Vietnam were held to a 0-0 draw by Myanmar on Tuesday as the duo remained locked in the top two positions in group A of the AFF Suzuki Cup.
Both teams went into the meeting with two wins, and the draw lifts them to seven points apiece from three games, a point above third-placed Malaysia with one round of group games remaining.
The top two teams in the tournament's two groups advance to next month's semifinals. A win for Myanmar over Malaysia in their next match, on Nov. 24, would ensure both Vietnam and Myanmar progress.
The closest either side came to scoring on Tuesday was when Nguyen Van Toan had the ball in the back of the net 13 minutes from time, only for his effort to be ruled out for offside.
Cambodia, meanwhile, picked up their first win of the campaign under Japanese coach Keisuke Honda, with a 3-1 victory over already-eliminated Laos.
It was not enough to keep the Cambodians' hopes of a place in the next phase alive, however.
Chan Vathanaka and Prak Mony Udom put Cambodia two goals up before Somxay Keohanam pulled one back for Laos 14 minutes from time, only for Keo Sokhpeng to restore the Cambodians' cushion a minute later.
The tournament continues on Wednesday, when defending champions Thailand take on the Philippines in a top-of-the-table meeting in group B, while Singapore host East Timor.