Vietnam put themselves in a strong position to reach their first AFF Suzuki Cup final in a decade with a 2-1 away win in the first leg of their semi-final against the Philippines on Sunday.
Nguyen Anh Duc headed the visitors into the lead after 12 minutes at Panaad Stadium, but Patrick Reichelt restored parity with a close-range volley on the stroke of half-time.
However, Phan Van Duc put the 2008 champions back in front early in the second half, as they grabbed the upper hand ahead of the return game at Hanoi's My Dinh Stadium on Thursday.
The winners over the two legs will meet Malaysia or Thailand, who drew 0-0 in Kuala Lumpur on Saturday, in the final of Southeast Asia's biennial tournament later this month.
Vietnam grabbed the early initiative in Bacolod when Doan Van Hau's lofted ball caught out the Azkals defence, with Anh Duc looping a header over goalkeeper Michael Falkesgaard and into the net.
Van Duc and Nguyen Quang Hai both came close to extending the lead for the visitors but the Filipinos got back on level terms in first-half stoppage time.
Following an exchange of passes on the left flank, Phil Younghusband sent an accurate cross for Reichelt to volley home from close range.
The hosts deserved their equaliser, but they were caught cold again at the start of the second half as Nguyen Trong Hoang chipped the ball over the top of the defence for Van Duc to beat the offside trap and slot easily past Falkesgaard.
It could have got worse for the Filipinos as Adam Reed's deflection forced a fine reflex save from Falkesgaard.
The Philippines goalkeeper then made good stops to keep out a pair of efforts by substitute Ha Duc Chinh, while Nguyen Cong Phuong shot wide after a great run through the home defence.