The Malaysian ladies started the day's action at the Singapore Indoor Stadium with a 3-2 victory over their Vietnamese counterparts in the only women's quarter-final of the day.
The Malaysian men advanced to the last four with 3-0 victory over Cambodia, either side of wins for Singapore and Thailand.
Singapore proved far too strong for LAOS PDR, winning 3-0, before Thailand triumphed 3-2 over Vietnam in the day's final match.
In the Malaysian men's match, Lee Chong Wei and Chong Wei Fen proved far too strong for their Cambodian opponents, before the doubles pair of Tan Wee Kion-Goh Wei Shem wrapped up the tie.
Lee, playing in his final SEA Games, was satisfied with the result after their strongest side was selected for the tie.
"It is important that we fielded our full team today so that we can get a feeling of the court for tomorrow," Lee told reporters in Bahasa.
The Malaysian women's team had to call on all their resolve after both Lim Yin Fun and Ho Yen Mei lost their singles matches, as Vietnam took a 2-0 lead.
But victories for Amelia Anscelli-Soong Fie Cho and Goh Jin Wei levelled matters, before Vivian Hoo and Woon Khe Wei sealed the victory in the final doubles match.