Gagner, who entered with five goals all season, broke loose for four goals and four assists — the first eight-point game in the NHL since Pittsburgh star Mario Lemieux did it on Dec. 31, 1988, against New Jersey.
Gagner fell two points shy of tying the league mark, set by Toronto's Darryl Sittler on Feb. 7, 1976.
"I didn't think I would ever be mentioned in the same breath as Gretzky or Coffey," said the 22-year-old Gagner, selected all three stars of the game. "You never expect to do something like this.
"It's a great lesson to never set limits. The great players who played here never did that. It was just one of those games where everything went in and just a great feeling."
Hall, who set a career high of his own with four points in the game, only wanted to talk about Gagner's night.
"I feel like a bit of a pigeon with four points tonight," he said. "It was just a crazy night. Every time we got the puck in the offensive zone, especially in the third period, it ended up on Sam's stick and he made a great play with it. I'm really happy I was able to be on the ice with him. It's a really cool moment."
It was the second time this season that the Blackhawks have given Edmonton fans plenty to cheer about. Chicago lost 9-2 to the Oilers at Rexall Place in November.
"It was really fun for our fans to see something like that tonight," Oilers coach Tom Renney said. "Sam was having the time of his life and so were his linemates and the entire team.
"It's been one of those years where you are looking for things to hang your hats on and feel good about and it doesn't get much better than this. It puts a smile on your face in a tough year.
"People will remember this game for a while."
"We really got away from our game plan and opened it up a little and they really made us pay," Sharp said. "We need to be better in a lot of areas and we're obviously not happy at all. We've gotten away from what makes us a good team.
"We got caught up in scoring goals and playing on the wrong side of the puck. It wasn't good enough as a team. We need to play defense first and we'll get our chances from there."
The Oilers responded less than 2 minutes later as Gagner earned his first point of the night. With a long pass, Gagner sprung Hall, who chipped in his 18th of the season past Chicago goalie Corey Crawford. Hall has scored in three straight games.
Gagner then tied it just more than 7 minutes later when he picked up his own rebound, circled behind the net and scored on a wraparound.
The Oilers took a 3-2 lead with 7 minutes remaining in the second as Whitney ripped a shot from the point while on the power play for his first of the season. Gagner earned the assist.
Chicago tied it 2 minutes later on a short-handed 2-on-1 as Dubnyk gave up a rebound to Sharp, who buried his second of the night.
Gagner made it 4-3 only 2 minutes into the third with his second goal of the night. Whitney's shot sailed over the net but bounced in front for Gagner to put past Crawford.
The Oilers chased the Chicago goalie 2 minutes later when Barker fluttered a shot from the point that Crawford waved at as it went into the top corner. Gagner earned his third assist and Ray Emery replaced Crawford.
The Blackhawks got a goal back 6 minutes into the third as Bolland made a no-look backhand swat at a puck that squirted past Dubnyk.
Gagner completed the hat trick 30 seconds later to make it 6-4, as Hall spun around and found Gagner streaking down the ice for his sixth point of the game.
But he wasn't done yet.
Eberle and Hall did terrific tic-tac-toe passing to get Gagner the puck, and he slapped his fourth goal of the game into a wide-open net as Emery slid to keep up with the play.
With their hats already thrown onto the ice earlier in the period, one fan resorted to throwing a shoe after the goal.
"I was hoping that would be the end of it because if he scored another one we might have seen other paraphernalia that we didn't want to see," Renney said with a laugh.
Gagner then added his eighth point of the game by making a prefect feed to Eberle, who scored his 20th of the season with 4 minutes left.
Dubnyk finished the game with 43 saves on 47 shots.
Crawford let in five goals on 28 shots. while Emery allowed three goals on 13 shots.