Ales Hemsky, Jordan Eberle and Taylor Chorney also scored for the Oilers, who halted a three-game skid and won for only the third time in their last 15 games overall (3-11-1).
Nikolai Khabibulin finished with 24 saves in the victory.
Loui Eriksson scored the lone goal for the Stars, whose wheels are starting to fall off after a very promising first half of the season. Dallas enjoyed a five-game win streak in mid-January, but is 2-7-1 since and fell into a three- way tie for second place with Anaheim and Phoenix in the Pacific Division.
Dallas goaltender Kari Lehtonen allowed four goals on 30 shots.
Eberle’s 12th goal of the season opened the scoring with 1:58 to go in the first period.
At the 7:40 mark of the middle frame, the Oilers gained a 2-0 edge with a power-play goal. After Mark Fistric went to the penalty box for hooking, Horcoff and Tom Gilbert helped set up Chorney’s first NHL goal.
Eriksson’s 19th goal of 2010-11 — a power-play tally assisted by Lehtonen and Jason Williams — at 16:31 of the second cut the Dallas deficit in half, but Edmonton responded less than two minutes later.
Skating 5-on-4 due to another Fistric minor (cross checking), the Oilers passed the puck around the perimeter of their offensive zone until Hemsky held control along the right half-wall. Hemsky then drifted to the top of the circle and faked a shot before his pass into the low slot was successfully redirected past Lehtonen by Horcoff with 1:50 remaining before intermission.
Hemsky capped the scoring 28 seconds into the final stanza. Horcoff carried the puck through the neutral zone along the left side and passed across to Hemsky, who split two defenders, moved in on a breakaway and lit the lamp with a backhander at the left post.
Chorney became the eighth Oiler this season to record his first career goal…This marked just the fourth time this season that Edmonton scored more than one power-play goal in a game…Khabibulin was winless in his previous 14 starts prior to this victory…Dallas, which has now dropped five straight road games, remained stuck on 699 victories since the franchise relocated to Texas from Minnesota…It was Hemsky’s 10th goal of 2010-11…The Stars were 1-for-3 on the power play, and the hosts ended 2-for-6 with the extra skater.