Second seed Tsonga, who also lifted the title here in 2009, had it far from easy against former world number three Davydenko but eventually saw off the Russian in straight sets, winning 7-6 (7/4) 7-6 (10/8).
There was plenty of other home success on Wednesday, with top seed Richard Gasquet cruising through his second-round match while his compatriots Julien Benneteau, Nicolas Mahut and former champion Michael Llodra were all first-round winners.
Gasquet needed just 70 minutes to see off the challenge of Slovenian Blaz Kavcic 6-3 6-3 and the world number nine will next face either fifth seed Ivan Dodig or Tobias Kamke for a place in the semi-finals.
Seventh seed Benneteau, meanwhile, defeated Dutchman Jesse Huta Galung 6-1 6-4 while number eight Mahut beat compatriot Kenny De Schepper 7-6 (7/2) 6-3.
Llodra, who has reached the final here three times in the last five editions and won in 2010, saw off Lukas Lacko 6-3 7-6 (7/2).
Other first-round victors on Wednesday were Ricardas Berankis, Roberto Bautista-Agut and Jan-Lennard Struff.
Source: DSG
