The 19-year-old nailed his fifth goal with 28 seconds left on the clock to seal the win and cap an incredible comeback after the Power trailed by 20 points with 22 minutes played in the final term.
It ended a run of four successive Port goals, which included an incredible off-break bounce from Angus Monfries' snap that cut the margin to two points and set the stage for Wingard to write his name into Showdown legend.
Five talking points: Adelaide v Port Adelaide
It was the first Showdown to be decided by less than a goal in the encounter's 35-game history.
Wingard was by far the game's best player and further stamped his reputation as Port's most exciting player since Gavin Wanganeen by taking out his first Showdown Medal.
Wingard was by far the game's best player and further stamped his reputation as Port's most exciting player since Gavin Wanganeen by taking out his first Showdown Medal.
Power coach Ken Hinkley said Wingard was a lock for All Australian selection this year.
"He's a special player, he's had an incredible season and there's absolutely no doubt in my mind if not before today he's going to be in the All Australian side surely," Hinkley said.
"He's had an amazing year and today was the icing on the cake for him and his year bar none has been first class at this football club.
"It just shows his character, he believes in himself, he believes in his teammates and his job was to finish off their great work."
Click here to vote for the three best Port Adelaide players from the game
Adelaide was best served by Brad Crouch and David Mackay through the midfield, while Patrick Dangerfield and Lewis Johnston kicked four goals apiece.
From the opening bounce the pressure was high and despite Matthew Lobbe offering the Power's midfielders first use, the Crows snuck out to an early lead.
Jared Petrenko executed a brilliant chase and tackle to catch Paul Stewart holding the ball, but Stewart badly broke his left wrist in the process and was quickly subbed for youngster Sam Colquhoun.
An infringement by Power skipper Travis Boak brought Lewis Johnston within range to nail his second goal early in the second quarter with his renowned goal-kicking skills on full show.
But the Power then piled on seven goals to one for the term with Gray and Monfries combining twice to gift each other majors as Port Adelaide led by 21 points at half-time.
Adelaide was best served by Brad Crouch and David Mackay through the midfield, while Patrick Dangerfield and Lewis Johnston kicked four goals apiece.
From the opening bounce the pressure was high and despite Matthew Lobbe offering the Power's midfielders first use, the Crows snuck out to an early lead.
Jared Petrenko executed a brilliant chase and tackle to catch Paul Stewart holding the ball, but Stewart badly broke his left wrist in the process and was quickly subbed for youngster Sam Colquhoun.
An infringement by Power skipper Travis Boak brought Lewis Johnston within range to nail his second goal early in the second quarter with his renowned goal-kicking skills on full show.
But the Power then piled on seven goals to one for the term with Gray and Monfries combining twice to gift each other majors as Port Adelaide led by 21 points at half-time.
Young guns Crouch and Wingard were dominating with 17 and 15 first-half possessions respectively while Hamish Hartlett got in on the act too with two brilliant goals.
Click here to vote for the three best Adelaide players from the game
The Crows needed a spark quickly and they got it seconds into the third quarter with Johnston involved in consecutive plays as Petrenko finished on his left before nailing a second in five minutes.
Johnston kicked his third – a massive 70m bomb that bounced through – but it was 19-year-old Mitch Grigg who set AAMI Stadium alight in the third term as Adelaide piled on seven goals for the quarter to lead by two goals at the last change.
Wingard halved the margin within seconds of the final term's start but the pressure-cooker atmosphere took its toll on both sides as decision-making and skills took a downward turn.
Colquhoun closed the gap to a point before three straight goals to Adelaide, capped by Grigg's clever pass to Henderson for a major, gave the Crows what appeared to be a match-winning lead.
However, the Power weren't done yet.
The win puts eighth-placed Port Adelaide two games clear of Carlton with four games remaining, while the loss finally puts an end to Adelaide's admittedly flimsy hopes of returning to the finals. The Crows are now 13th, four games and percentage out of the top eight.
The Crows needed a spark quickly and they got it seconds into the third quarter with Johnston involved in consecutive plays as Petrenko finished on his left before nailing a second in five minutes.
Johnston kicked his third – a massive 70m bomb that bounced through – but it was 19-year-old Mitch Grigg who set AAMI Stadium alight in the third term as Adelaide piled on seven goals for the quarter to lead by two goals at the last change.
Wingard halved the margin within seconds of the final term's start but the pressure-cooker atmosphere took its toll on both sides as decision-making and skills took a downward turn.
Colquhoun closed the gap to a point before three straight goals to Adelaide, capped by Grigg's clever pass to Henderson for a major, gave the Crows what appeared to be a match-winning lead.
However, the Power weren't done yet.
The win puts eighth-placed Port Adelaide two games clear of Carlton with four games remaining, while the loss finally puts an end to Adelaide's admittedly flimsy hopes of returning to the finals. The Crows are now 13th, four games and percentage out of the top eight.
Crows coach Brenton Sanderson said that while his side's shot at playing finals was now over, he wouldn't pick players just to see what they could offer the club in 2014.
"We lose and we're out, it seems," he said.
"We've still got four games though to finish the year off.
"We'll still keep picking our best 22 each week ... regardless of experience or age.
"We'll do our very best to fight this season out ... until that final siren in the last quarter of the last game of the year."
Ollie Wines hunts the footy during Port Adelaide's win over Adelaide at AAMI Stadium: Picture: AFL Media
Harry Thring is a reporter for AFL Media. Follow him on Twitter: @AFL_Harry
ADELAIDE 3.2 5.6 12.10 15.13 (103)
PORT ADELAIDE 2.1 9.3 11.4 17.5 (107)
GOALS
Adelaide: Dangerfield 4, Johnston 4, Wright 2, Petrenko 2, Grigg, Brown, Henderson
Port Adelaide: Wingard 5, Hartlett 3, Gray 3, Schulz 2, Monfries 2, Butcher, Colquhoun
BEST
Adelaide: Crouch, Dangerfield, Johnston, Mackay, Grigg, Vince
Port Adelaide: Wingard, Hartlett, Gray, Boak, Cornes, Schulz
INJURIES
Adelaide: Nil
Port Adelaide: Paul Stewart (broken wrist)
SUBSTITUTES
Adelaide: Mitch Grigg replaced Jarryd Lyons in the third quarter
Port Adelaide: Sam Colquhoun replaced Paul Stewart (wrist) in the first quarter
Reports: Nil
Umpires: Stewart, Ryan, Jeffery
Official crowd: 43,368 at AAMI Stadium
