In his first taste of South Australia's biggest sporting rivalry, Steven Motlop has become a Port Adelaide hero with a last-gasp goal to break Adelaide hearts in the 44th Showdown.

Motlop’s major, with 21 seconds remaining, handed the Power a 14.11 (95) to 14.6 (90) victory in a thrilling contest that snaps a five-game Adelaide winning streak and levels the all-time ledger at 22-all.

"It's enormous," Power coach Ken Hinkley said.

"We knew all the talk was about 0-5, it was pretty emotional for us all that we were able to somehow find a way to win tonight.

"They made some big plays ... great sides do that to you.

"I was just so proud of our boys that we had structure in place for those last two plays and they both came off."

Power star Robbie Gray claimed his third Showdown Medal as best on ground for his six-goal performance, including five in a dazzling third quarter.

Down by 17 points late in the last quarter, the Crows looked to have stolen the premiership points after Mitch McGovern's 50m set shot gave them the lead with less than a minute on the clock.

But Motlop had other ideas, kicking on the run from 45m, the ball sailing through the posts and sparking rapturous applause from the 50,967-strong crowd.

"We went to a structure which was about trying to close that game out," Crows coach Don Pyke said.

"We'll review that, from a structural view point we got things reasonably right, it was execution.

"We had two guys collide and the ball spilled out, that's footy.

"Sometimes when you lose by under a goal, it's a bit like the old saying, sometimes you're the bug, and sometimes you're the windshield, tonight we ended up being the bug."

Down by 27 points in the second quarter, the Power looked to have the game in the bag when they went ahead by 17 points late in the last term.

But the Crows found another gear – Betts kicking his third major, skipper Taylor Walker nailing a huge captain's goal from outside 50m and McGovern sensationally putting them back in front.

Power star Robbie Gray claimed his third Showdown Medal as best on ground for his six-goal performance, including five in a dazzling third quarter.

Everything turned on its head in the pivotal third term, with the Power booting 7.5 to 2.2 to take a 12-point advantage into the last quarter.

It's a huge result for the Power, who are back inside the top eight at 5-3 ahead of next Saturday's trip to China to face Gold Coast.

The depleted Crows, with a huge injury list that includes Rory Sloane, Kyle Hartigan, Riley Knight and Brodie Smith, suffered their first loss after three straight wins to drop to 5-3.

Down by 27 points in the second quarter, the Power looked to have the game in the bag when they went ahead by 17 points late in the last term.

But the Crows found another gear – Betts kicking his third major, skipper Taylor Walker nailing a huge captain's goal from outside 50m and McGovern sensationally putting them back in front.

High-profile recruit Tom Rockliff showed why the Power signed the free agent to a four-year deal with a powerful midfield performance, finishing with a game-high 31 disposals, in his first game back after spending the past two weeks in the SANFL in his comeback from a calf injury.

Power defender Tom Jonas was absolutely superb and unlucky to have his direct opponent Betts finish with three goals.

Midfielder Sam Powell-Pepper was strong in his first game back after missing the past four due to a club suspension and related fallout for an off-field incident.

Winger Rory Atkins and midfielders Cam Ellis-Yolmen, Matt Crouch and Hugh Greenwood were the best for the Crows.

MEDICAL ROOM 
Port Adelaide: The Power reported a clean bill of health.

Adelaide: In his first game back from a hamstring injury, skipper Taylor Walker felt some tightness in his glute in the second quarter. After spending some time off the ground, he returned to play out the game, and kicked a crucial goal in the fourth quarter. Ruckman Sam Jacobs had back spasms, but also finished the game.

NEXT UP 
The Power take on the AFL's biggest road trip when they head to China to face Gold Coast in Shanghai at Adelaide Arena at Jiangwan Stadium next Saturday, 1.15pm local time (2.45pm ACST/3.15pm AEST). The Crows have a six-day turnaround before hosting the Western Bulldogs at Adelaide Oval on Friday night, 7.20pm (ACST).

PORT ADELAIDE  1.3   4.6   11.11  14.11 (95)
ADELAIDE            4.2   8.3   10.5    14.6 (90)

GOALS
Port Adelaide: R.Gray 6, Wingard 2, Ryder 2, S.Gray, Boak, Powell-Pepper, Motlop
Adelaide: Betts 3, Ellis-Yolmen 2, McGovern 2, Walker 2, Atkins, Jenkins, Douglas, Seedsman, Lynch 

BEST 
Port Adelaide: R.Gray, Jonas, Polec, Rockliff, Jonas, Neade, Ryder
Adelaide: Laird, Atkins, Crouch, Talia, Gibbs, Ellis-Yolmen                                                                          

INJURIES 
Port Adelaide: TBC
Adelaide: Walker (glute), Jacobs (back spasms)

Reports: TBC

Umpires: Donlon, Haussen, Meredith

Official crowd: 50,967 at the Adelaide Oval