It was Glencross' first hat trick of the season and third of his career.
Glencross, who played 26 games for Edmonton in 2007-08, went into the game with seven goals in 26 games the season.
"It was a great game, a complete team game. We didn't give up too much and we stuck to our game plan," Glencross said. "We had all four lines going for the 60 minutes and it was good for Ramo to get a win in his first game back, he played really well for us. It's nice to get everyone back and get rolling again."
Flames goaltender Karri Ramo, making his first start since Feb. 1 because of a knee injury, made 24 saves.
The Flames (29-35-7) scored four goals in a span of 3:05 to take control of the game in the second period. Mike Cammalleri, Matt Stajan, Paul Byron and Glencross scored to give the Flames a 5-1 lead. Flames defenseman Mike Giordano scored in the first period. Kevin Westgarth and Glencross, with two goals, extended the lead in the third.
"What a great game. We wanted to redeem ourselves from [Friday] night's game," Flames coach Bob Hartley said, referencing a 6-5 home loss against the Nashville Predators. "We had a good video session [Saturday] morning. I could see that the boys were not very impressed with the performance from [Friday] night. We just worked very simple, we were very effective and we scored some great goals."
Jeff Petry scored the lone goal for the Oilers (25-38-9), who have lost two straight.
Petry gave the Oilers an early lead, scoring on the power play at 4:34 of the first period. The Oilers defenseman fired a shot from the point that went through Ramo's pads. It was the first shot Ramo faced in the game.
Giordano tied the game at 8:29, stepping into a point shot that found its way through Fasth.
Cammalleri put the Flames up 2-1 at 4:13 of the second, capitalizing on an Edmonton turnover to start the Calgary outburst. Oilers left wing Matt Hendricks had his clearing pass intercepted by Mikael Backlund, who found Cammalleri in front for an easy one-timer for his 23rd goal. Cammalleri has 13 points during a seven-game point streak.
"It's been a challenge for us to produce offense this year," Cammalleri said. "It's nice to see pucks go in like they did. You don't expect to score eight goals every night, but it's nice to get that feeling where you feel like the puck is going to go in the net for us."
Stajan converted on a penalty shot 1:07 later, beating Fasth with a backhand shot. Stajan was awarded the penalty shot after being slashed by Oilers defenseman Mark Fraser while on a breakaway, causing him to lose control of the puck.
It was Stajan's first goal since rejoining the team following the death of his infant son.
"That one means a lot," Stajan said. "It's been obviously not easy, and that one was for the little guy. It felt good and it gave us some puck-luck after too. We'll move on now, and I'll remember that one forever."
Stajan pointed to the sky after scoring the goal and then skated to the bench, where he was embraced by his teammates.
"It was just a reaction," Stajan said. "In life, obviously, some things are more important, but you have to move on and remember. To score the way I did, on a penalty shot, it's a little bit of a nice story for my family and my wife, and I think it's something that I'll have a stamp on forever. We got the puck and we'll keep that with him forever."
Byron scored 40 seconds later to give Calgary a 4-1 lead. He took a pass from Cammalleri in front and beat Fasth.
Despite the Oilers calling a time out in an attempt to regroup, the Flames scored a fifth goal at 7:18, when Glencross fired a shot off a rush over Fasth, who was replaced by Scrivens after the goal.
"Within that three or four minutes span, we made at least one mistake on four consecutive shifts, it seemed, and every time it ended up in our net," Oilers coach Dallas Eakins said. "We just could not recover from it. It just went deeper and deeper."
Glencross increased the lead to 6-1 at 4:50 of the third period, taking a pass from Stajan in front and beating Scrivens.
Westgarth scored at 5:27 to give the Flames a 7-1 lead. Glencross scored at 13:19 to complete the hat trick and put the Flames up 8-1.
"That was probably the longest last 15 minutes of a game that I have ever been involved with," Eakins said. "I apologize to the fans who were here tonight and had to watch it. It was painful on the bench, and I'm sure it was painful in the stands. We hope it is just a blip on the radar because we have been playing pretty well lately."
The margin of victory was the largest ever by the Flames against the Oilers in Edmonton. Calgary won the season series between the teams with the victory, winning all three games at Rexall Place. The Oilers won the two games played in Calgary.
"We unraveled a bit," Oilers left wing Taylor Hall said. "I don't want to say that we are embarrassed, because we are not embarrassed in here. I think we need to work a little smarter in areas. The compete level was there at times, but for the most part they out-battled us, and that can't happen."
The Flames return home to host the San Jose Sharks on Monday. The Oilers face the Sharks on Tuesday.