Tkachuk squeezed a sharp-angled wrist shot between the pads of Coyotes goaltender Antti Raanta with 33 seconds remaining in extra time.
Tkachuk’s OT winner Oct. 31 in Nashville was a highlight-reel, between-the-legs stunner touted as a candidate for the NHL’s goal of the year.
“This one was just a normal shot,” Tkachuk said with a chuckle Tuesday.
“This year is kind of the first time I’m starting to play consistently 3-on-3, so just still trying to get used to it.”
The Flames trailing 3-1 late in the third period, Tkachuk and Mark Giordano scored in a 59-second span to send the game to overtime.
Johnny Gaudreau also scored for Calgary (9-7-2). David Rittich made 34 saves including five in overtime.
“We really had no business other than Ritter to win that game in my opinion,” Tkachuk said. “We played better in the third, but in the first (period) we played right into their hands.”
The 21-year-old winger, who signed a three-year, US$21-million contract extension in September, scored the equalizer in Nashville with 39 seconds remaining in regulation and the spectacular winner with just two seconds left in OT.
Tkachuk generated Tuesday’s OT winner on an extended shift.
“I recognized that they had a couple guys that were tired over there that were out there for a full shift before me,” he explained.
“I thought ‘why not try to take advantage of one more time?’ And did one more kind of lap and then got the puck and put it in.”
Clayton Keller, Christian Dvorak and Vinnie Hinostroza countered for the Coyotes (9-4-2).
Raanta got the start for Arizona after Darcy Kuemper picked up the OT win the previous night in Edmonton. The Finn posted 39 saves in the loss.
“We had four breakaways. We had three or four empty nets to make it 4-1, but we didn’t,” Coyotes head coach Rick Tocchet said. “Their goalie played really well tonight. That’s what I saw.”
With Rittich pulled for an extra attacker, Giordano threaded a low shot through traffic to score at 17:19 of the third period.
Tkachuk sparked the comeback scoring at 16:30. He beat Raanta with a shot from the top of the circle for a power-play goal while Arizona’s Barrett Hayton served a tripping penalty.
Hinostroza pounced on a turnover behind Calgary’s net and beat Rittich’s glove at 10:31 for his first of the season.
Gaudreau halved a 2-0 deficit with a power-play goal at 17:16 of the second period.
The winger ended Calgary’s 0-for-13 run with a man advantage. Calgary’s power play was 2-for-6 in the game, while Arizona was scoreless on five chances.
Gaudreau redirected a Tkachuk cross-ice pass by Raanta to halt a 12-game scoreless drought.
After Raanta rebuffed a breaking Mark Jankowski to open the period, Dvorak tipped an off-speed Phil Kessel shot past Rittich at 4:09.
Rittich denied Michael Grabner on a breakaway with his right pad with two and a half minutes remaining in the period.
Keller scored for the visitors at 8:29 when Calgary turned the puck over in its zone near the blue-line. Nick Schmaltz in the high slot dished to Keller for a top-shelf, one-timer.
Calgary winger Milan Lucic served the second game of his two-game suspension for punching Blue Jackets winger Kole Sherwood on Saturday.
Calgary is at home to the New Jersey Devils and the Coyotes host Columbus on Thursday.