WEST Coast has cemented its early-season form and notched its fifth straight win, shaking off a plucky St Kilda to win by 53 points at Etihad Stadium on Saturday.

After staring down two spirited fightbacks from the young Saints, the Eagles played with the authority of a top-four team in the final term to win 20.11 (131) to 12.6 (78).

The win and their superior percentage leaves them clear in second place on the ladder for another week with a 6-2 record in their best start to a season since 2012.

Gallery: All the action from West Coast's win at Etihad

Adam Simpson's midfield was the catalyst for the win, led by Luke Shuey (28 possessions and nine clearances) and Brownlow medallist Matt Priddis (31 and seven), who fed on the clean ruck work of Nic Naitanui (37 hit-outs, 15 to advantage).

Classy first-year onballer Liam Duggan, who was recruited with pick No.11 in last year's NAB AFL Draft, also played an important role, shutting down opponent Leigh Montagna in the crucial third quarter and finishing with 23 possessions and eight inside 50s.

After watching a 37-point lead cut to 12 points at the main break, Simpson said he challenged his players to rediscover their best football.

"I didn't really do too much in terms of strategy … it was more about the players intent to maintain a standard that has been there for a month," the coach said.

"I reckon we dropped that standard a little in the second quarter, and I thought we went back up to what has been making us pretty solid and then the result started to take care of itself."

The Saints, who were already undersized in defence after Luke Delaney's hip injury, were left counting the cost with Sam Fisher (hamstring) and Jimmy Webster (concussion) not finishing the match.

Webster was substituted at half-time after he was caught high in a clash with teammate Sean Dempster, who was running back with the flight of the ball.

The half-back had earlier been taken off the ground bleeding, following a late spoil from Elliot Yeo that could leave the in-form Eagle in trouble with the Match Review Panel.

After falling more than six goals down late in the first quarter, St Kilda dominated the second quarter and kicked five goals to one, building their fightback on superior tackling pressure.

Flying high: West Coast's team song

The cut the gap to seven points twice in the third quarter, but each time West Coast's midfielders responded and got on top, with forward Josh Kennedy also kicking two of his four goals as the Eagles rebuilt their margin.

St Kilda coach Alan Richardson was left to rue a slow start that had similarities to his team's round six opening against the Western Bulldogs, which they were able to overcome.

"That's when the fight starts and we weren't up for the fight," Richardson said.

"I was very pleased that the guys were able to turn that around and change the momentum of the game.

"They (West Coast) are a good team. They're really aggressive with the way they move the ball and they're very aggressive with the way they defend."

The Eagles broke the Saints' spirit late in the third term and booted the last four goals of the match to blow the margin out in what had been an otherwise competitive match.

St Kilda midfielders Jack Steven (36 possessions and 12 tackles) and David Armitage (32 and eight clearances) continued their strong seasons, while Mav Weller was dogged in his match-up on to Mark LeCras.

ST KILDA          1.2  6.4  10.5   12.6    (78) 

WEST COAST   7.3  8.4   15.6  20.11  (131) 

GOALS
St Kilda: Sinclair 2, Bruce 2, Weller 2, Newnes, Templeton, Roberton, Savage, Membrey, Schneider
West Coast: Kennedy 4, Hill 4, Yeo 3, Cripps 3, LeCras, Sinclair, Shuey, Priddis, McInnes, Sheppard 

BEST
St Kilda: Steven, Armitage, Newnes, Weller, Schneider, Montagn
West Coast: Shuey, McGovern, Priddis, Yeo, Naitanui, Duggan, Gaff 

INJURIES 
St Kilda: Jimmy Webster (concussion), Sam Fisher (hamstring)
West Coast: Mark Hutchings (back tighteness) replaced in selected side by Jackson Nelson

SUBSTITUTES
St KIlda: Blake Acres replaced Jimmy Webster at half-time
West Coast: Scott Selwood replaced Jamie Bennell in the third quarter

Reports: Nil 

Umpires: Foot, Kamolins, Armstrong

Official crowd: 23,598 at Etihad Stadium