Vietnam's Ly Hoang Nam and Sumit Nagal of India celebrates their Wimbledon boy's double title on July 12.

Vietnam’s Ly Hoang Nam teamed up with Sumit Nagal (India) to beat Reily Opelka (US) and Akira Santillan (Japan) in straight sets in the final of the Wimbledon boy's doubles event in London Sunday.

Nam, 18, from the southern province of Tay Ninh became the first Vietnamese tennis player to win a Grand Slam title.

Seeded only No. 8. and with little expectations against higher-ranked opponents, Nam and Nagal played well to score a surprise victory after winning the first set in a tie-breaker and romping home 6/4 in the second.

Opelka, the 18th seed, had earlier won the boys’ singles title.

Nam said: “Nagal and I coordinated well. Nagal volleys well. I have improved. I don't know how to express my happiness at this win.”

In the semi-final they were run close by Kecmanovic and Ruud after winning the first set in a tie-breaker. They won the third set 12/10.

“After being beaten in boy’s singles, I told myself to try harder in the doubles. I did not expect to reach the final. It was great and I am glad for that.”

The win fetches Nam 90 points and he hopes a ranking in the doubles top ten.

His coach, Tran Duc Quynh, said the title also means an automatic place in next year’s Wimbledon.

Nam has a career-high ATP singles ranking of 1440 he achieved in April.

In the eagerly awaited men’s single’s final, Novak Djokovic of Serbia successfully defended his title, beating ageing master Roger Federer 3-1.