Lao beat Cambodia 11-7 to win the last of the action in this year's HSBC Asian Five Nations, taking the division 5 title.
As a result, Lao also retains the Mekong Cup trophy, contested by the two nations, for a fourth consecutive year.
They become the sixth nation to win their HSBC Asian 5 Nations division in 2011, joining Japan, Korea, Chinese Taipei, China and Qatar.
Home side Lao made the best of difficult conditions, particularly in the first half when they dominated both territory and possession, while their greater discipline and lower penalty count contributed to another deserved win.
Chris Mastoglio opened the scoring with a penalty in the 17th minute before Chaleunesouk Anousith scored their first try for an 8-0 half time lead.
After the break Mastoglio notched another penalty before Cambodia rallied and managed to reduce their penalty count and secure possession. After a period of prolonged pressure, lock Souanrado Nong went over from close range to close the gap to four points and the Cambodians were back in the contest.
However, spurred on by their vocal home support, Lao managed to hold off the Cambodians in a tense final 10 minutes to secure the win.
Asian Rugby now prepares for the Sevens season and the Shanghai Sevens, the opening event of the inaugural HSBC Asian Sevens Series kicking off at the end of August.
HSBC Asian 5 Nations 2011 winners
Top 5 - Japan
Division 1 - Korea
Division 2 - Chinese Taipei
Division 3 - China
Division 4 - Qatar
Division 5 - Lao