Hawthorn's premiership defence is hanging by a thread after suffering a shock 20-point AFL defeat to West Coast at a rain and windswept Subiaco Oval on Saturday night.

Jarryd Roughead and Lance Franklin combined for nine goals but it wasn't enough as three wonder goals from boom Eagles recruit Nic Naitanui in the final term inspired West Coast to a 16.11 (107) to 13.9 (87) triumph.

To add to the Hawks' horror trip, forward Mark Williams could be set for a lengthy stint on the sidelines after suffering a knee injury during the third quarter.

Roughead's fifth goal of the match early in the final quarter put Hawthorn four points ahead but Naitanui, in just his second AFL match, turned the game on its head in the blink of an eye.

The 19-year-old had gathered just two possessions in the opening three quarters but sent the 31,441 fans into raptures with three brilliant pieces of play in the final quarter.

The first came when he smothered Jordan Lewis on the goal line, regathered the ball, shook of the Hawk's tackle and snuck the ball inside Brad Sewell to boot his first goal of the match and snatch back the lead for West Coast.

Five minutes later, Naitanui extended the lead to eight points when he expertly soccered the ball in for a goal after it had come off the back of a pack.

Josh Kennedy and Ben McKinley booted goals shortly afterwards to extend the Eagles' buffer to 19 points, but Naitanui had one more piece of magic left in him.

The dreadlocked cult hero smothered a handball from Hawks defender Tom Murphy 70m out from goal and with nobody guarding Hawthorn's goal, made a dash for the line.

But his bounce on the rain-logged ground failed to come up.

So, with Murphy hot on his hammer, Naitanui put on the afterburners, scooped up the ball and snapped truly off his right, dribbling the ball through.

It capped off a remarkable night for the Eagles, who trailed by 18 points early in the second quarter but were able to secure the win due to their superior use of the gale-force wind.

The loss leaves Hawthorn in ninth place with a 6-7 record and a tough match against Western Bulldogs to come on Saturday night, while West Coast improve their record to 4-9 after snapping a five-game losing streak.

Naitanui, leading the ruck in the absence of Dean Cox, finished with 14 hit-outs while Quinten Lynch (26 possessions, 23 hit-outs), Brad Ebert, Chris Masten, Matt Rosa, Andrew Embley, Matt Priddis and David Wirrpanda were also crucial in the win.

Mark LeCras booted four goals in the first half while Josh Kennedy chipped in with two after the long break.

Sam Mitchell was inspirational for the visitors with 40 possessions and 13 clearances, while Sewell (32 possessions), Chance Bateman (29) and Lewis (28) were also prolific.

Roughead was the dominant forward with 5.1 while Franklin's four goals were gifts, with three of them coming from point-blank range.

Hawthorn lost premiership pair Stuart Dew and Stephen Gilham before the match.

West Coast coach John Worsfold said he was elated with Naitanui's efforts in the final term.

"He was a big part of us winning the game with that quarter," Worsfold said.

"A lot of players did a lot of work over the four quarters to keep us in that position and then to have someone who could just do a couple of those things is great.

"He's in the very early stages of what's going to be a promising career and we are conscious of that."

Williams will undergo a scan on his knee on Monday but Hawthorn coach Alastair Clarkson was hopeful it was nothing more than a knock.

Clarkson said Dew pulled out due to a slight quad injury he picked up at training, while Gilham was forced out with a virus.

"It was a pretty even contest between the two sides all night but the game literally slipped away from us," Clarkson said.

"We just couldn't control the ball in the back end of the ground and I think they kicked six goals from turnovers in our back 50.

"A lot of them were easy goalsquare type of goals."

Brought to you by AAP © 2024 AAP