The Stars have captured three in a row for the first time this year and they ended the Ducks' four-game winning streak.
Lehtonen was routinely facing 40 shots a game in the opening days of the season, but the Dallas defense has quickly made major improvements to produce the recent run of success.
Nick Bonino tipped in a shot for the only Anaheim goal with 4:37 to go in the middle period. Loui Eriksson provided Dallas insurance by scoring on a wrist shot with 7:14 left in the third.
While based in Minnesota for 26 seasons, the current Dallas franchise won 758 games. Friday's victory was the Stars' 758th in its 19 years in Texas.
Jonas Hiller started in goal for the Ducks, but suffered a lower body injury after stopping 14-of-16 shots and was replaced by rookie Viktor Fasth.