Second seed Berdych, who ousted the French top seed in Shanghai last week, came from a set down to win 4-6 6-4 6-4 in two hours and 28 minutes.
The victory means Czech number one Berdych, 27, is all-but guaranteed the sixth qualification spot for the season-ending Finals at the O2 in November.
France's Tsonga, also 27, currently lies in the eighth and final ATP Race spot and should qualify for the Finals. Both men have now won two titles this season.
Tsonga took the first set with a single break and seemed on course for victory when he went 4-2 up in the second.
But the 6'5" Berdych rallied to win four games on he bounce, levelling at one set apiece, and he broke at the last in the decider to leave Tsonga beaten again.
"London is always a goal every season," said Berdych when asked about the World Tour Finals. "You have to play well the whole year to qualify.
"It will be special for me, if I make it for the third year in a row. I then hope to do well for Czech Republic in the Davis Cup final at home."