Robertson cut across the crease and lifted a backhander over goalie Jacob Markstrom in overtime.
“You give Robertson an inch, he takes it and he scores,” Flames defenseman Rasmus Andersson said.
Robertson has 41 goals to become the first player with consecutive 40-goal seasons since the franchise moved from Minnesota to Dallas for the 1993-94 season. He's the third in team history, joining Dino Ciccarelli (three in a row in 1985-86, 1986-87 and 1987-88) and Dave Gagner (1989-90, 1990-91).
“They put me out there to try to produce,” Robertson said. “A lot of guys on this team are having fantastic seasons. It kind of bleeds into my game. That success translates from our team to individuals.
“We’re doing really well in the standings right now. We want to keep it that way. But that sure helps a guy like me to achieve that milestone.”
Joe Pavelski, Radek Faksa, Wyatt Johnston and Jani Hakanpaa also scored to help Central-leading Dallas snap a two-game losing streak and end a six-game trip with four victories. Jake Oettinger made 33 saves.
Elias Lindholm, MacKenzie Weegar, Blake Coleman, Nick Ritchie and Andersson scored for Calgary. Markstrom stopped 20 shots. The Flames are four points behind Winnipeg for the Western Conference’s last wild-card playoff spot.
“We did a good job climbing back in the game,” Weegar said. “Battling down to the last minute, going into OT, it comes down to one play and we’ve got to start making that play.”
Robertson tied it at 4 with 1:50 left in the second period. Andersson gave Calgary the lead at 9:53 of the third period, and Hakanpaa tied it with 7:51 left.
“We had two losses to this team in our barn,” Robertson said. “One especially we’d really love to get back. It feels good to get one in their building and get the two points.”
NOTES: With 88 points, Robertson is closing in on Mike Modano’s Dallas record of 93 points set in 1993-94. Bobby Smith set the franchise record with 114 in Minnesota in 1981‑82. ... Dallas opened its trip with a victory in Buffalo and took two in Seattle. The Stars then lost in Vancouver and Edmonton. ... Dallas ended a four-game skid against Calgary. ... The Flames were coming off a 7-2 win Thursday night at Vegas, their first road victory over the Golden Knights.
Stars: Host Seattle on Tuesday night.
Flames: At Los Angeles on Monday night.