West Coast chief executive Trevor Nisbett has hailed the Eagles' upset win over Adelaide on Saturday as a victory for the club's alignment with East Perth.
The Eagles took a depleted team to face Adelaide's strongest team of the season at Adelaide Oval.
But the Eagles won by 31 points without Dean Cox, Matt Rosa, Scott Selwood, Darren Glass, Beau Waters, Brad Sheppard, Sharrod Wellingham and Elliot Yeo.
Nisbett said the ability of players to step straight into the AFL and perform showed how important the WAFL alignment had been.
"It's showing effects now, when the guys come in," Nisbett said.
"They're all playing the same footy and the same style. I think that'll improve as the years go on and this is the first sign of it.
"We made four changes and the guys stepped up and played the same brand of footy.
"Daws (East Perth coach Brian Dawson) coaches the same way and the boys at East Perth are trying to play the same sort of brand that Adam (Simpson) wants.
"It's great credit to the coaching staff and players."
This is the first season that all of West Coast's players are with East Perth, while Fremantle are aligned to Peel. Last year, some players still played for the WAFL club they were recruited from.
Only 12 Eagles from Saturday's team haven't played in the WAFL this year and several have mostly played for East Perth.
Fremantle and West Coast each pay $450,000 a year for the right to have their players at one club but Nisbett said it was vital they had the same conditions as their opponents.
"It was an expensive fight but a good fight for our players," Nisbett said.
"The players all have a soft spot for the club they came from if they're West Australian boys but they understand the business needs to go back and play together. That's what they've done and they've done it really well."
The win kept West Coast's small finals chance alive. They have games against finals contenders Collingwood, Essendon and Gold Coast in the run home, leaving their fate in their own hands.
The win over Adelaide was the side's fourth interstate victory this season and the second time the Eagles had beaten a team that was inside the eight at the time of the game.
Nisbett said he was happy with the side's progression under first-year coach Simpson.
"It's great for Adam because I think it would have been dreadful for him if he didn't start to see some of the results of the hard work," Nisbett said.
"I think we have improved on last year. Our percentage says we have.
"The way the guys are applying themselves is pretty noticeable.
"Hopefully we'll just keep improving from here.
"I'm not sure there is ever a turning point, but certainly it was a really good win against really good opposition.
"We've got to do that more often, for longer. Our next step is Collingwood."