Vietnam beat fancied rivals Aspire, a team from Qatar's football academy, by two goals to one in Gia Lai Province on Thursday to advance to the semifinals of the Under-21 International Football Tournament.
Both teams have booked their semifinals spots after beating Malaysia in their first matches of the fifth edition of the international football event sponsored by Thanh Nien.
However, the Vietnamese team was considered the underdog because less than a week ago, Aspire had drawn 2-2 with Vietnam's U23 team and finished second behind South Korean students at the Ho Chi Minh City Cup.
The U21 victory over Aspire was therefore gave a pleasant surprise to Vietnamese spectators and TV viewers.
The host team played defensive football but launched dangerous counterattacks and took the lead after 15 minutes when striker Huu Khoi fired a powerful shot past Aspire custodian John Felagha.
Both teams played fast football and less than 10 minutes later, Vietnam doubled the lead when captain Bui Xuan Hieu volleyed Nhat Nam's corner kick into the back of Aspire's net.
The players from Aspire began to look impatient after conceding the second goal. They tried much harder and had their chances but Vietnamese custodian Thanh Diep proved equal to the task.
In the second half, the visitors were able to pull one back after a Jasper Chibueze strike hit Vietnamese defender Thanh Nam and changed direction, making it impossible for Thanh Diep to stop the deflection.
Both teams continued to play fast and create more chances but their attackers failed to capitalize.
In Group B, Thailand's U21 players played well to draw 1-1 with Iran, to remain in second place on goal difference.
In the semifinals on Sunday, Vietnam will play Thailand while Iran will take on Aspire for a spot in the final to be played on Tuesday.