They did it in the last minute.
They will next play Thailand on March 26 in a match that will decide who finishes the qualifiers in top spot.
As the clock ticked, Trieu Viet Hung found himself in between the bigger Indonesian defenders to nod the ball home past of goalkeeper Awan Setho Raharjo.
Vietnam, with home advantage, dominated from the start attacking down both flanks. They had most of the possession in the opening 15 minutes but couldn’t beat Raharjo.
At the other end the defenders were guilty of making mistakes and Thanh Chung nearly scored an own goal slicing a clearance that fortunately for him fell the wrong side of his own post.
Vietnamese keeper Bui Tien Dung also kept Indonesian at bay, keeping his net safe in the first half.
Unhappy with what he was seeing, coach Park Hang-seo made three changes at half-time but the substitutes couldn’t break down the Indonesian defence.
Meanwhile keeper Dung made a serious mistake when he cleared ball to Indonesian striker Marinus within his box. But the Hanoi FC player successfully stopped the finish.
Vietnam were given their fourth corner kick in the third minute of the extra time.
Talented midfielder Nguyen Quang Hai’s cross found Hung who cheered up thousands of supporters in the stands.
Winning the second match Vietnam rank second in the table behind Thailand on goal difference who trounced Brunei 8-0 in an early match of the group.
Thailand with two wins currently tops group K. As the host of 2020 AFC U23 Championship, Thailand is already in, while Vietnam needs to top the group or become the best second-placed team.