Song Ui-young scored six minutes from time to open the result of the match that saw Quang Ninh Coal playing with 10 men in the last 15 minutes at Jalan Besar Stadium.
Song scored twice – including the winning goal in the 84th minute – while the rest of the goals for the hosts went to Faris Ramli seven minutes after the break.
Congolese Patiyo Tambwe levelled the scores in the 32nd minute for the visitors when he headed home Nghiem Xuan Tu’s cross. Just eight minutes later, it was 2-1 for Quang Ninh Coal when captain Vu Minh Tuan slotted his shot into the bottom corner.
Striker Mac Hong Quan was sent off for a second bookable offence in the 75th minute.
Home United claimed all three points after their first win in this Cup to rank second in the group.
Yadanarbon FC of Myanmar are on top with four points.
Quang Ninh Coal sit at the bottom with one point.
In the next fixture on April 5, Quang Ninh Coal will host Home United at the Hanoi’s My Dinh Stadium.