Olivier Giroud bagged a first-half hat-trick against the international side, while Alex Oxlade-Chamberlain, Chuba Akpom and Ignasi Miquel found the net, as the Gunners continued their preparations for the new Premier League campaign.
Wenger's side now have 14 goals from two friendly victories during their tour of Asia and the Frenchman is happy with his side's development, especially due to the difficult and humid conditions.
"It was a game played with good pace and a good spirit. For us, of course, it was a good preparation for the season," Wenger told the club's official website.
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"We learned first of all to play at a high pace, because it was a pacy game. We learned to suffer physically because we had two hard sessions yesterday and we practised today. The conditions, the climate, are difficult for us so we had to learn to suffer a little bit and keep our concentration to keep the level of our game high."
Vietnam found a consolation goal 12 minutes from time through Tran Manh Dung's mistimed volley and Wenger admitted that he was pleased to see the home fans celebrate something.
"Overall they have the basic quality and it was great to see the enthusiasm and the happiness when they scored the goal," he added. "It was one of the few times in my life that I enjoyed when an opponent scored.
"It was such a great moment in the stadium and the enthusiasm of the crowd was so big that of course they deserve to be happy.
"We will certainly try to come back because we had such a positive experience but I am not the only one to decide on that. Vietnam must want us back as well."