Looking to exact some revenge on their provincial counterpart after dropping their last Red Deer rookie meeting 6-3 in 2018, the Oilers owned much of the Westerner Park Centrium ice in the first period.
The Orange & Blue outshot the Flames Rookies 13-7 after 20 but Calgary keeper Artyom Zagidulin made several key stops to keep the visitors from trailing.
Ostap Safin got the period's best opportunity, walking out from the corner while on the power play and getting three consecutive cracks at Zagidulin. The winger tried to go 5-hole twice and on his third attempt, flipped the puck behind Zagidulin but it somehow skittered out the crease.
The script flipped in the second as the Flames controlled possession but couldn't do damage on goalie Dylan Wells.
The goaltender started the period off with a sliding breakaway save then later made another similar stop when Dillon Dube broke in all alone.
Wells' night ended with 18 saves on 18 shots, as Stuart Skinner took control of the crease midway through the middle stanza.
"I felt good tonight," said Wells. "I just wanted to get out there, feel pucks, track the puck well and keep it simple and efficient.
"Overall, I'm happy with my first performance of the year."
With the scoring low, the penalties racked up. The Oilers were forced to kill three minors but the nastiness escalated. Beau Starrett was blindsided by a punch from Montana Onyebuchi, with both players receiving offsetting infractions.
Later in the frame, Cooper Marody was stapled at Calgary's bench, causing Vincent Desharnais to dance with Martin Pospisil.
Fisticuffs aside, the Flames outshot the Oilers 15-7 in the second but neither side found the back of the net to enter the third deadlocked at 0-0.
"We didn't love our second period," said Head Coach Jay Woodcroft. "We felt we turned the puck over and that led to some of their transition chances going the other way."
The clubs traded powerplays in the third but no goal lamp illuminated, sending the game to overtime.
Just over a minute into the extra frame, an errant pass found its way to Dube, who broke in off the rush with Phillips. Phillips received a pass and flipped it over Skinner's pad for the winning tally.
Edmonton and Calgary will play a rematch on Tuesday at the Scotiabank Saddledome. Puck drop is at 7:08 PM MT and will be livestreamed on EdmontonOilers.com, YouTube, Facebook and Twitter.
"I always look forward to playing these guys," said Day. "We'll tighten a couple of things up and get back out there."