They scored five impressive tries, and held the Roosters scoreless for 77 minutes.
In recent years contemplating a similar scenario would have been labelled an April Fool's day hoax.
Previous Warriors sides have been virtually incapable of winning without Johnson – their best offensive weapon – and the absence of Mannering (their strongest defender) is usually accompanied by a resigned groan from Warriors supporters.
But not this year. Not with this side. They have balance and structure across the park, which has meant the reliance on individuals has gone. And they are starting to look like a real footy team, the kind that the Warriors faithful have been crying out for.
They have prop forwards that are giving momentum, with Bunty Afoa particularly impressive in the first half and Adam Blair showing why Stephen Kearney was so keen to lure him across the Tasman. Tohu Harris and Leivaha Pulu offer weapons on both edges, and look the best balanced second row pairing at Mt Smart since 2011.
They outmuscled the big name Roosters pack, and shut down their dangerous backline.
Blake Green has been a revelation – and had his best match in a Warriors jumper so far today – with his double play to save a try, then kick a 40-20 a few tackles later absolutely superb.
Mason Lino, who has always looked a solid performer in his limited previous NRL opportunities, was superb, with his pinpoint bomb for David Fusitua's try demonstrating the confidence of the Samoan half.
Issac Luke had a busy match and Roger Tuivasa-Sheck came up with another try saving tackle as he looked for revenge against his previous club.
The most exciting element of this victory is the knowledge that this Warriors' team has improvement in them, and will only get better as combinations continue to develop.
Perspective needs to be retained, as the Roosters were awful, completely disjointed and lacking cohesion, but a lot of their malaise came from the incessant Warriors pressure.
After last week's memorable comeback Johnson warned that "no one was getting carried away."
They might be now.
