Nystrom scored the tiebreaking goal with 2:20 left and the Stars rallied for a 3-2 victory over the Ottawa Senators on Thursday night.
Nystrom took possession of the puck behind the Ottawa net, drifted to the circle and fired a shot past goalie Craig Anderson for his ninth goal in 20 games since he was acquired in a trade with Minnesota on Oct. 12.
Stars coach Glen Gulutzan remembered when Nystrom was an NHL rookie with Calgary, and now sees many of the same attributes in the older Nystrom.
"I had a history with Eric, because I saw him play eight years ago in a different organization, and when I saw him break into the NHL, he got chances because he worked so hard," Gulutzan said. "I just think you see some maturity now with him, and getting around the net, he has some more poise. He still works as hard as he ever did and he's putting them in.
"So it's a credit to a guy who, for the year he's had, is very resilient."
Dallas dealt for Nystrom primarily because the Stars needed his salary to reach the minimum payroll under the cap, but Nystrom has become a scoring threat.
Nystrom had four goals for the Wild last season.
"There's no special formula to what we're doing," Nystrom said. "We're just working hard, getting in on the forecheck, shooting the puck and getting to spots where we can get shots off. It's not like we're doing anything fancy, we're just grinding away and it's been working. It's a lot of fun playing with those guys."
Milan Michalek had given the Senators a 2-1 advantage at 11:42 of the final period.
Daniel Alfredsson took a shot from the right point that rebounded off goalie Andrew Raycroft to the left circle. Michalek beat two Stars to the puck and then beat Raycroft with a shot for his team-high 15th goal.
But the Senators sat back late and couldn't protect their lead.
"I thought the first 55 minutes we played real well, but unfortunately we played defensive the last five minutes," Ottawa coach Paul MacLean said. "We couldn't get the puck out of our end when we had opportunities.
"When you have a lead in this league, you have to continue to play hard. You can't take things for granted."
Dvorak and Steve Ott also scored for Dallas, 4-1-1 in its last six games. Raycroft made 33 saves.
Erik Condra had Ottawa's other goal, and Anderson stopped 29 shots.
Dvorak got Dallas even at 2 with 5:34 left in the third period when he converted Mike Ribeiro's centering pass for his third of the season.
Ott added a power-play goal for Dallas, and Raycroft made a glove save on a point-blank attempt by Michalek just before the final buzzer as the Senators had an extra attacker with Anderson on the bench.
Raycroft, filling in for injured regular Kari Lehtonen (groin), made back-to-back starts for the first time this season, and his last save turned out to be his best.
Condra gave Ottawa a 1-0 lead when he worked a 2-on-1 with Jared Cowen and connected on a wrister from the slot at 7:07 for his third of the season.
Ott's deflection of Toby Petersen's pass toward the net tied it at 1 at 9:38 of the first period on Dallas' second power play. It was Ott's fifth goal.
Dallas had been 0 for 22 with the man advantage before Ott scored.
The Stars are 8-1-1 in one-goal games. ... Ottawa D Filip Kuba was scratched after sustaining an undisclosed upper body injury in the previous game. ... Senators RW Chris Neil missed his ninth straight game (sprained ankle), but is practicing and is close to returning. ... In addition to Lehtonen, the Stars are without captain Brenden Morrow (multiple injuries), D Alex Goligoski (broken thumb), D Trevor Daley (back) and forward Adam Burish (broken hand). ... Attendance continues to lag. The crowd was announced as 10,490, but there were several thousand fewer in the seats. ... The teams met for the only time this season. ... Dallas is 4-1-1 in its last six against Ottawa.