A heroic four-goal haul by Justin Westhoff inspired Port Adelaide to a remarkable nine-point comeback victory against arch rivals Adelaide on Sunday.

The Power came from 31 points down in the third term to post a stunning 17.16 (118) to 16.13 (109) triumph at AAMI Stadium.

Westhoff kicked all his goals in the second half as Port booted nine of the last 12 goals of the game to bank their third consecutive win.

While Westhoff was best afield, the unbeaten Power were also sparked by captain Travis Boak (three goals) and Chad Wingard, who kicked three goals.

Adelaide spearhead Taylor Walker booted three majors while on-ballers Rory Sloane and Scott Thompson were solid performers.

When Walker kicked his third in the 11th minute of the third quarter, the Crows skipped 31 points ahead and appeared home.

But Westhoff triggered a comeback which was defined by a game-turning incident late in the quarter.

Adelaide midfielder Matthew Wright had a set shot at goal from 45 metres to give his side a two-goal buffer, but inexplicably handballed to his teammate Matthew Jaensch, charging from behind.

But Crows players didn’t factor in Port veteran Jay Schulz, who was hot on Jaensch’s heels and tackled the Adelaide player, who was forced into a wild handball.

The ball sailed straight to Port, who swept the ball down field and captain Boak goaled to level the scores at three-quarter time.

The Power then rode their momentum before a 40,707-strong crowd with a commanding last quarter.

Wingard kicked all three of his goals in the final stanza, his last coming after being collected high by Adelaide’s Bernie Vince, who was reported for charging.

The Crows, now with one win and two losses, host Western Bulldogs next Sunday while Port travel to play Gold Coast on Saturday night.