Geelong captain Patrick Dangerfield has been hospitalised after his Cats suffered a 38-point away loss to new AFL ladder leaders Port Adelaide.
The Power produced seven goals in a magical 19 minutes in their 16.14 (110) to 11.6 (72) triumph at Adelaide Oval on Thursday night.
Geelong's Brownlow medallist Dangerfield copped a heavy knock to the back in a collision with Port's Dan Houston in the second quarter.
He played out the game in obvious discomfort but was then sent to hospital for observation.
"He got that knock and just progressively seized up more and more," Geelong coach Chris Scott said.
"And to the point where, he's a warrior, but it didn't look to us like he couldn't move.
"But he said he wanted to sort of keep trying.
"It was clear he just couldn't have an impact on the game."
Port, extending their club-record winning streak to 11 games, replace Collingwood in top spot on the ladder.
And coach Ken Hinkley's outfit, with 12 wins and two losses, will keep top billing for at least a week, with the Magpies (11-2) having a bye this weekend.
The Cats (six wins, seven losses) retain ninth spot but could slip as low as 12th by the end of the weekend.
Port slipped 21 points behind in the second quarter and were 13 points down three minutes into the third term.
But an improbable Sam Powell-Pepper goal - a dribbling effort from the boundary line - sparked a match-defining scoring spree.
Powell-Pepper's strike was the first of seven consecutive Power goals in a 19-minute burst that turned their deficit into a 30-point advantage.
"We have got some consistent themes to the way we play and tonight we demonstrated those themes in that third quarter again," Hinkley said.
"We have won 11 in a row ... collectively they have been remarkable."
Port forwards Jeremy Finlayson (four goals) and Todd Marshall (three goals) were superb, while utility Dan Houston (31 disposals) continued his excellent form.
Acting captain Ollie Wines (28 touches), Zak Butters (23, one goal) and Connor Rozee (25) were also influential.
Geelong's Gary Rohan also booted three goals while Zach Guthrie (26 possessions), Max Holmes (24), Mitch Duncan (20) and Isaac Smith (20) were chief ball-winners for the visitors.
The Cats, with Rohan scoring his three majors, booted 6.2 to 2.6 in an impressive opening term.
And they maintained a 21-point lead midway through the second quarter but Port kicked two late goals to reduce their halftime deficit to seven points.
Port went 13 points down in the third before clicking into top gear with seven unanswered goals in 19 brilliant minutes.
After trailing by 17 at three-quarter-time, Geelong crept within 12 points early in the final term.
Powell-Pepper then again stole the spotlight. With brute strength, he shrugged a Guthrie tackle and snapped accurately to trigger a final Power flourish - they scored the last four goals.