Playing on weary legs at the very end, Hiller stuck around long enough to get his first win for the Flames.
Hiller made 49 saves and Mikael Backlund scored at 4:35 of overtime, lifting Calgary to a 2-1 victory at Chicago on Wednesday.
"Tonight was probably not our best effort, but we found a way and worked hard and got better the longer the game went," said Hiller, who began his career with Anaheim and signed a $9 million, two-year contract with Calgary in July.
Dennis Wideman also scored for the Flames, who were coming off a 3-2 shootout win at Nashville on Tuesday.
The Blackhawks controlled the action for much of the game, enjoying a whopping 50-18 advantage in shots on goal. But Hiller was outstanding and Backlund used a wrist shot to beat Corey Crawford on the goaltender's glove side for his first goal of the season.
"I was happy that we didn't have to go to the shootout," Hiller said. "I had a little tired legs there at the end."
Andrew Shaw scored in the third period and Crawford had 16 saves in Chicago's first loss in three games.
The overtime began with a nice stop by Crawford on Paul Byron's breakaway opportunity just 40 seconds into the extra period. Brad Richards had a chance to win the game for the Blackhawks, but his tip off a nice pass from Duncan Keith went wide.
"They stole the game," Chicago's Marian Hossa said. "We had so many shots after the first period, and we just kept going. We played well, but we couldn't put the puck in the net. Their goalie, he deserves all the credit."
The Blackhawks played keepaway for much of the first two periods, but Hiller stepped up and the Flames jumped in front at 11:55 of the second. Joe Colborne won a faceoff with Jonathan Toews and sent the puck back to Wideman, who let loose with a long slap shot that went off the stick of Blackhawks rookie Trevor van Riemsdyk and into the net.
That was the only goal until the Blackhawks were successful on their seventh power play with 5:45 left in regulation. With Wideman in the penalty box for hooking, Shaw tipped Patrick Sharp's long slap shot past Hiller for his second goal.
Chicago had a couple chances for the tiebreaking score in regulation, but was unable to connect. Hiller stopped Patrick Kane's backhander in the final seconds.
"Our best shots, we probably had six or seven A-plus chances that didn't even get a shot on net," Blackhawks coach Joel Quenneville said. "We were looking for a better play, missed shot, blocked, too tight or missed the net. Those were the ones that didn't even add up on the scoresheet as far as shots. But those were the quality chances we missed."
The Blackhawks outshot the weary Flames 18-2 in the first, but Hiller's solid play kept the game scoreless. He stopped an open Kane with about 4 1/2 minutes left in the opening period, and denied Jeremy Morin on consecutive shots in the second.
Daniel Carcillo also misplayed a prime opportunity 6 1/2 minutes into the game after Ben Smith's drive and dish created an open side of the net for the winger. Sharp had a nice look in the second, and then slammed his stick against the glass after Hiller made the save.
"We played with fire," Calgary coach Bob Hartley said. "Hills gave us an unbelievable game and our penalty killing I think was the story with Jonas' performance."
Before Wideman's goal in the second, the Flames' best scoring opportunity was Byron's short-handed breakaway midway through the first. Byron beat Crawford, but he shot it off the inside of the right post.
Calgary had another good look five minutes into the second, but Crawford was there to stop Brian McGrattan.
NOTES: LW Brandon Bollig played 7 1/2 minutes in his first game in Chicago since he was traded to Calgary in June. Bollig made his NHL debut with the Blackhawks in 2012 and spent three seasons with them. ... Blackhawks D Michal Rozsival (upper body) is back at practice and could return for Saturday's game against Nashville. ... Flames LW Lance Bouma is day to day with a facial injury. Calgary also scratched RW David Jones and D Deryk Engelland with lower-body injuries. ... RW Kris Versteeg (lower body) and D Kyle Cumiskey were the other scratches for Chicago.
Jay Cohen can be reached at http://www.twitter.com/jcohenap