The second-seeded Frenchman saved three break points in the last game before sealing his victory.
Playing in his second tour final after losing in Melbourne, Tsonga fired big forehands to outplay Djokovic at the baseline and at the net.
Djokovic, ranked No. 3 in the world, looked sluggish at times. He ended the match by lobbing Tsonga's serve long.
The $576,000 Bangkok tournament was only the Frenchman's second since returning from a three-month layoff following knee surgery.
In the men's doubles final, Top seeds Lukas Dlouhy and Leander Paes combined to win their first team ATP title with a 6-4, 7-6(4) victory over Americans Scott Lipsky and David Martin at the Thailand Open in Bangkok on Sunday.
The Czech-Indian duo fired five aces, won 74% of points on serve and converted two of four break points to secure the victory in 1 hr., 16 min.
"It’s a great feeling to win the whole thing and I think if we keep working like this we can win more tournaments," said Dlouhy.Individually, the 35-year-old Paes has now won 40 ATP doubles titles, while Dlouhy, 10 years his junior, has compiled five.
"I think we played high-level tennis and when they came back in the second set we just stepped it up and we just focused on the basic things. I hope that we can keep it like this and we can enjoy the rest of the year and we are looking forward to playing the Masters Series events."
"It’s always special stepping on the court with Lukas because not only does he complement my style of playing but he’s also teaching me things," commented Paes.
"It’s interesting that, after playing for so many years, to have a partner who’s also teaching me a few things is really beautiful."
(Image via PORNCHAI KITTIWONGSAKUL/Robert Cianflone/AFP/Getty Images)