Geelong have crashed to an upset 30-point loss to Port Adelaide, but believe versatile veteran Mark Blicavs has avoided a serious knee injury.

The Power, with Jason Horne-Francis notching a career high in disposals, logged a shock 13.17 (95) to 10.5 (65) Anzac Day triumph at Adelaide Oval on Saturday night.

Geelong ace Blicavs damaged a lateral ligament in his left knee, but coach Chris Scott had "a level of optimism" it would only be a short-term injury.

"They (medicos) are hopeful it's not serious," Scott said.

"He was pretty upbeat as well, but he's - you know the Monty Python skit, he could have his arm chopped off and he'd still be positive about it, he's that kind of guy."

The Power move to three wins and four losses, while the Cats are four and three.

Port's win was triggered by a dominant display from Horne-Francis, who amassed a career-best 34 disposals - he also booted two goals, along with a dozen clearances - and spearhead Mitch Georgiades, who had 10 shots at goal for 4.6.

Ruckman Jordon Sweet (31 hit-outs, one goal) and acting captain Zak Butters (30 possessions) were also standouts, while recruit Corey Durdin kicked two goals.

"We've obviously been building with our game plan and confidence, so super rapt for the players to play in a game like that and get the result," Power coach Carr said.

Geelong star Bailey Smith (30 disposals) was prolific, Jeremy Cameron slotted three goals but was largely well held by Lachie Jones, and Shannon Neale kicked two.

Captain Patrick Dangerfield had only four disposals - the second-lowest tally in his 363-game career - but coach Scott said the Brownlow Medal winner wasn't carrying an injury.

The Cats, with prime movers Smith and Max Holmes (25 touches) busy and Cameron booting two goals, raced to a 24-9 break after 20 minutes.

But the strong opening was punctuated by Blicavs' injury, hyperextending the lateral ligament in his left knee when he swung a kick that met Port's Butters body.

After Geelong lost the 301-gamer, the Power's Georgiades soon stole the spotlight, kicking 2.4 for the quarter.

Ruckman Sweet also threaded a stunning checkside as Port rallied to a six-point quarter-time lead, 4.6 to 4.0.

The hot streak of Georgiades extended in the second term: 10 minutes in, he had scored 3.5 and Port held a 13-point buffer.

The Power took that advantage into halftime, 7.8 to 6.1, with Georgiades' eight shots at goal the most in a half this season.

The Power took that advantage into halftime, 7.8 to 6.1, with Georgiades' eight shots at goal the most in a half this season.

Playing in front of a 41,164-strong crowd, Port logged an inaccurate 2.7 to 1.2 in the third quarter and took a 24-point break into the final quarter.

Horne-Francis added another highlight to his eye-catching game with the opening goal inside a minute.

And when Georgiades, whose only blemish was wayward shooting, potted his fourth major soon after, the Power were bound for one of the shock victories of the season.