It was Bourque's second multi-goal game of the season and the 19th of his 677-game NHL career. He also netted two in a 3-2 victory over the Winnipeg Jets on Nov. 11.
MacKinnon continued his strong play with a goal and an assist, extending his point streak to four games.
He opened the scoring 5:50 into the first period as he received the puck on a chip off the wall by Rantanen, who finished with two assists, raced into the Edmonton zone on a 2-on-1 and sniped a wrist shot over the glove of Talbot.
MacKinnon now has three goals and five assists in his last four contests.
"He was good, real good early," Bednar said of MacKinnon. "It's got to be 60 minutes. It can't be 50, 40 minutes. We need our whole team to go for 60."
It seemed as if the Avalanche had to play down a man for much of the night, as the Oilers had six power-play opportunities and scored on two of them. Edmonton entered Wednesday with the ninth-best road power play in the league.
"They're a dangerous power play. You look at that top unit, they have some really good players in that unit, and they make things happen," Duchene said. "We have to be better there, but you got to give them a little bit of credit too. We got to bear down."
Despite the errors throughout, the Avs still had a chance to pick up their first three-game winning streak of the season. Instead, they'll have to work their way back from below .500 on Saturday when they host the Vancouver Canucks.
"We talked about it in the (second) intermission, it was a big (third) period for us and a good chance for us to jump a few teams in the standings and get a wild-card spot and three to ride home," Bourque said. "We laid an egg."