Defending champions Singapore maintained their perfect record in this year's AFF Suzuki Cup to earn top spot in Group A with victory over Indonesia in Jakarta.
Baihakki Khaizan and Shi Jiayi scored as Singapore continued their dominance over the South East Asian giants, extending their unbeaten run against Indonesia to seven games.
Indonesia, however, have also qualified for the knockout phase of the competition after earlier wins over Myanmar and Cambodia.
Both Indonesia and Singapore will find who they play in the semi-finals after Wednesday's final games in Group B, when Thailand face Malaysia and Vietnam take on Laos.
Baihakki gave Singapore the perfect start when, with barely three minutes on the clock, the defender rose to meet John Wilkinson's free-kick.
From there, the Singaporeans sat back and defended their lead with the home side finding it difficult to break through the well-organised backline despite an intense period of pressure from Benny Dolo's team.
Although they controlled the tempo of the half and had the majority of the possession, Indonesia fashioned little in the way of clear-cut chances.
Budi Sudarsono was denied by Baihakki after Arif Suyono sent in a fine cross in the 34th minute while Bambang Pamungkas went close with a header late in the half.
Just seconds earlier, though, the Singaporeans could have doubled their lead and made life exceedingly difficult for Indonesia.
Captain Indra Sahdan Daud broke towards the home side's penalty area but, rather than sending the ball towards the on-rushing Wilkinson, he shot across the face of goal, with Agu Casmir just failing to connect with the ball as he slid into the six yard box.
Five minutes after the restart, Singapore did manage to extend their advantage when Shi curled a right-footed free-kick around the defensive wall and beyond Markus Rihihina's outstretched left hand.
Two minutes later Muhammad Ridhuan should have sealed the result for the island state when he burst into the penalty area but the shot was dragged well wide by the full-back.
Budi went close to clawing one back for Indonesia 19 minutes from time, only to find the side netting, while, with just three minutes remaining, Singapore goalkeeper Lionel Lewis managed to keep the home side out when he palmed away Aliyudin's close-range effort.