Steen broke down the left side as part of a three-on-one, and his shot from just inside the faceoff circle trickled through Corey Crawford.
"You pick a spot," Steen said. "I don't know that it's really how hard it is. It's more where you put it."
Patrick Kane scored for the third consecutive game for Chicago. His coach, Joel Quenneville, said he was upset that his team gave up an odd-man break so late in a tie game.
"You've got to get that game to overtime," he said. "You take one (point), maybe two. You don't get none."
Game highlights: Rookie Sean Monahan had a goal and an assist in the first period, and the host Flames, after leading 3-0, held off the Canadiens 3-2.
Young Shark makes history
San Jose, Calif. — Sharks rookie Tomas Hertl scored four goals in a 9-2 win late Tuesday over the visiting Rangers.
At 19 years, 11 months, 4 days, the Czech center is the youngest player to do so since the Kings' Jimmy Carson (19 years, 8 months, 10 days) on March 30, 1988. Hertl went between his legs for No. 4.
Hertl, the 17th overall draft pick in 2012, leads the league in goals (six) and points (seven).
"It's crazy," Hertl said after the game. "This is a dream. I never (scored four) in the Czech League. I never had three. In the NHL, it's crazy."
Panthers goalies: Florida goalie Tim Thomas, who strained his groin Tuesday against the Flyers, said he doesn't expect to miss much time. Jacob Markstrom is expected to start tonight against the Lightning.
Discipline: Sharks defenseman Brad Stuart was suspended three games for a check to the head of Rangers wing Rick Nash on Tuesday. Nash played the rest of the first period but not afterward. The Rangers disclosed neither his injury nor status. … Islanders center Frans Nielsen was fined $5,000 for slashing Coyotes center Martin Hanzal on Tuesday.
Around the league: Leafs wing Joffrey Lupul will travel to Nashville for tonight's game but is questionable with a bruised calf sustained in a collision with Avalanche wing P.A. Parenteau on Tuesday. … Wild goalie Niklas Backstrom is day-to-day with a strained right knee sustained Tuesday when Predators wing Eric Nystrom crashed into him after being hauled down on a breakaway.
First Period—1, St. Louis, Tarasenko 2 (Berglund), 15:44. 2, Chicago, Kane 3 (Sharp, Toews), 17:01 (pp). Penalties—Brookbank, Chi, major (fighting), 1:59; Stewart, StL, major (fighting), 1:59; Lapierre, StL (boarding), 16:54.
Second Period—3, St. Louis, Backes 2 (Pietrangelo, Oshie), 8:37 (pp). 4, Chicago, Toews 1 (Kane, Sharp), 9:16 (pp). Penalties—Bickell, Chi (hooking), 7:23; Schwartz, StL (hooking), 9:01; Oduya, Chi (hooking), 19:31.
Third Period—5, St. Louis, Steen 3 (Pietrangelo, Bouwmeester), 19:38. Penalties—Bickell, Chi (roughing), 16:10; Toews, Chi (roughing), 16:10; Jackman, StL (roughing), 16:10; Sobotka, StL (roughing), 16:10. Shots on Goal—Chicago 12-9-7—28. St. Louis 13-14-7—34. Power-play opportunities—Chicago 2 of 2; St. Louis 1 of 2. Goalies—Chicago, Crawford 1-1-1 (34 shots-31 saves). St. Louis, Halak 3-0-0 (28-26). A—16,565 (19,150).
First Period—1, Calgary, Monahan 3 (Stempniak), 9:09. 2, Calgary, Baertschi 1 (Monahan), 18:33. Penalties—Bouma, Cal (high-sticking), 15:37.
Second Period—3, Calgary, Glencross 2 (Wideman, Hudler), 16:22 (pp). 4, Montreal, Subban 1 (Pacioretty, Markov), 17:46 (pp). Penalties—Galiardi, Cal (tripping), 4:35; Bouillon, Mon (boarding), 15:27; Giordano, Cal (tripping), 16:38.
Third Period—5, Montreal, Eller 4 (Galchenyuk, Subban), 10:40. Penalties—Subban, Mon (holding), 6:49; Subban, Mon (cross-checking), 18:11. Shots on Goal—Montreal 12-12-11—35. Calgary 5-11-9—25. Power-play opportunities—Montreal 1 of 3; Calgary 1 of 3. Goalies—Montreal, Price 1-2-0 (25 shots-22 saves). Calgary, MacDonald 2-0-1 (35-33). A—19,289 (19,289).