Pickett starred in the first half and Bayley Fritsch kicked three late goals for the Demons in their 12.11 (83) to 11.9 (75) victory in front of 88,019 fans at the MCG on Monday.
But there is concern for Mihocek, who was taken to hospital for scans after he was accidentally hurt in a Billy Frampton tackle.
A premiership Pie, Mihocek was playing his first match against his former team when he went head-first into the turf in the second quarter.
Play was held up for almost 10 minutes before Mihocek was driven off the field, but in a positive sign, the 33-year-old was moving his arms and communicating with medical staff.
"All our thoughts are with him at the moment," Dees coach Steven King said.
"He's getting scans and we're just waiting to see what happens there, but fingers and toes are crossed for him.
"We're obviously concerned. It didn't look great and when you see a player go down with issues around the head and neck, that's serious."
The first King's Birthday blockbuster and Big Freeze event since Neale Daniher's passing a fortnight ago was a cracker, with neither side leading by more than 16 points throughout.
There were eight lead changes - three in the final term - and both sides squandered multiple goal-scoring chances in the last few minutes.
Pickett missed a set shot and sent another kick on the run out on the full before seizing the decisive moment inside the final minute of play.
The Dees superstar was told by teammates to take his time for the previous set shot, but ignored thoughts of letting the clock tick down when he played on from his final mark and snapped truly.
"I was in a moment, seeing no-one there, so I played on and luckily enough I kicked it through to seal the game," Pickett told AAP.
"It was pretty special. I don't know how much time there was, but to get the goal after I missed two, and seal it, it was real good."
Pickett finished with 28 disposals, five clearances and three goals despite being well held by Ed Allan for most of the second half, and was awarded the Neale Daniher Trophy for his efforts.
Jack Steele (26 touches), Harvey Langford (27) and Tom Sparrow (23) also shone, ruck star Max Gawn and defender Jake Lever stood tall, and Harrison Petty kicked two goals.
Collingwood gun Nick Daicos starred with 35 disposals, six clearances and two goals, with brother Josh (30 touches) and Patrick Lipinski (28) also busy.
Dan McStay, Jack Buller and Jordan De Goey kicked two goals each.
Melbourne (8-5) move back into the top six, while Collingwood (5-7-1), who lost vice-captain Brayden Maynard to a dislocated shoulder in the second term, sit just outside the wildcard finals places after a fourth loss in five matches.
"We didn't take our chances when we had chances to hit the lead with a couple of minutes to go," Collingwood coach Craig McRae said.
"Then there's moments of them kicking goals from the boundary line and we missed our set shots.
"That's what I'm reflecting on at the moment.
"We're playing good footy and there's parts of our game that continue to improve, but ultimately we sit here with the same result."
McRae indicated Magpies vice-captain Maynard was expected to be sidelined for an extended period.
