Ranked outside the top-200, Tsonga returned to Montpellier to conquer the 17th ATP title and the first since Antwerp in 2017, defeating the 7th seed Pierre-Hugues Herbert 6-4, 6-2 in an hour and 13 minutes to become the seventh French victor of this event in nine years.
The 33-year-old Tsonga ranks No. 210 but will vault to around No. 140.
Herbert has now lost his three singles finals on the ATP Tour. France's Jo-Wilfried Tsonga in action during the match against Serbia's Novak Djokovic.
Cuevas, who earlier swept aside Aljaz Bedene in their weather-delayed quarter-final, took the second set but Pella produced a lethal forehand to advance to his fourth ATP Tour final 6-1 3-6 6-3.
I hope to be able to play the same tennis in the final.' Doubles specialist Herbert secured a fine 6-2 7-5 win over Czech Tomas Berdych, who had reached the final of the same event in 2012.
A break late in the opener left Tsonga serving for the set and he maintained that momentum to go a break up in the second.
He needed just 73 to defeat Herbert in straight sets, dropping just four points behind his first serve.
In a tight opening set, Tsonga earned the only two break points at 4-4.
In the other semifinal, Bulgaria's Marton Fucsovics rallied to beat Italy's Matteo Berrettini 5-7, 7-5, 6-3 in 2 hours, 13 minutes.