It was the third goal of the season for Jagr and the 668th in an NHL career that began in 1990.
Dallas has won back-to-back games for the first time this season. Edmonton suffered its fourth loss in a row.
Justin Schultz produced a power-play goal for Edmonton midway through the third.
Kari Lehtonen stopped 27-of-29 shots to pick up the victory. Devan Dubnyk suffered the loss while making 25 saves.
Dennis Rodman pledges to end trips to North Korea
Interpol investigating stolen passports on missing flight