The index dipped five points in the beginning of the day but quickly rose to close with a near 11-point gain.
It has risen nearly 77 points in the last eight sessions and is now at a near one-month high.
Foreign investors were net buyers for the fifth straight session to the tune of VND1.12 trillion ($49 million), highest since July 12, with strongest pressure on VHM of real estate giant Vinhomes and STB of Ho Chi Minh City-based lender Sacombank.
Trading value on the Ho Chi Minh Stock Exchange (HoSE), on which the index is based, fell 9 percent to VND19.32 trillion. The bourse saw 262 tickers gain and 116 lose.
The VN30 basket, comprising the 30 largest capped stocks, saw 20 tickers in the green led by GVR of Vietnam Rubber Group with a 4.2 percent gain, hitting a one-month high.
HPG of steelmaker Hoa Phat Group continued its recovery with a 2.7 percent gain.
TPB of private TPBank rose 2.3 percent, while VPB of private lender VPBank gained 2.1 percent.
Other gainers included MWG of electronics retail chain Mobile World, up 1.8 percent, and Asia Commercial Bank (ACB), up 1.4 percent.
Among the eight losing tickers, SAB of brewer Sabeco lost 1 percent, followed by MSN of conglomerate Masan Group with a 0.7 percent fall.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, rose 1.7 percent while the UPCoM-Index for the Unlisted Public Companies Market gained 0.47 percent.