The Panthers arrived in Auckland without five stars - Nathan Cleary, Isaah Yeo, Dylan Edwards, Liam Martin and Brian To'o - due to the travel factor from Origin II in Perth to New Zealand.
But the rookie outfit ambushed the third-ranked hosts 28-18 in their Saturday clash to bank a third straight win and continue their climb from the bottom of the ladder.
Currently in sixth, the defending premiers could finish inside the top eight at the end of the round for the first time since their Las Vegas win in the opening round.
While delighted by the victory, Cleary wasn't getting carried away by the ladder ramifications.
"It was a great win and a great performance but I like to just look at it as a little thing on its own because it's just such a long way to go," Cleary said.
"We'll finish where we deserve ... we're playing a bit of our brand of footy so at least we give ourselves a chance."
Cleary said the side were stung by their heavy loss to Newcastle in Bathurst in round 12 when they were also missing their Origin contingent.
"I definitely think that was probably the starting point - they just wanted to prove to themselves and everyone that we're certainly better than what we showed that night.Â
"We've tried to build a culture here where it doesn't matter who's playing and you deliver a certain standard and whether you win or not."
Winning seven of their past eight matches, the Warriors were expected to outclass Penrith but the Panthers' young halves Blaize Talagi and Brad Schneider stood up to steer the visitors home.
With Moses Leota leading the way up front with 147 run metres, veteran second rower Scott Sorensen also stood tall, scoring two of their five tries while exciting young winger Tom Jenkins also crossed.
The Warriors weren't helped by losing Marata Niukore to a head knock 10 minutes into the match and then winger Dallin Watene-Zelezniak, with fears he has a syndesmosis ankle injury.
Sorensen went on report for the tackle that ended Watene-Zelezniak's night.
Trailing 6-8 at halftime, the Warriors' hopes of a big finish were also hobbled as halfback Luke Metcalf struggled with a quad injury, although it's believed to be only a cork.
The Warriors edged ahead soon after the break through Jacob Laban but the full house at Go Media Stadium then had little to cheer about until a 78th minute consolation try by Moala Graham-Taufa.
In the meantime, the Panthers piled on a further three tries, with Talagi and winger Paul Alamoti getting in on the action, to seal the win.
Warriors coach Andrew Webster felt his team beat themselves.
"I don't look at the personnel of the opposition, I look at the way we play, our style," Webster said.
"If we played our best game tonight, and they played their best game, and we got beaten by that scoreline, then I'd be upset but we didn't play well.
"I think we beat ourselves tonight, and they were very good, the Panthers, but we just didn't get our game on at all."
