Livewire No.1 Nicoll-Klokstad powered through 314 metres from 30 runs as the Warriors wore down their rivals at a packed Go Media Stadium on Friday to break an eight-match losing streak against the Tricolours.
The game turned with 15 minutes remaining in what was a gripping struggle when Warriors five-eighth Chanel Harris-Tavita put up a bomb and chased through, leapt over Roosters captain James Tedseco, before regathering the ball to score.
It gave the Warriors their first lead of the night, and when exciting centre Ali Leiataua sliced through out wide to notch his second four-pointer six minutes later the victory was sealed.
In a ferocious defensive battle, both sides had plenty of opportunities with the ball, only to be thwarted by desperate try saves and a host of handling errors.
The Warriors dominated field position in the opening quarter of the game with line speed and swarming defence, often bringing three and four of their big forwards to the tackle.
Despite the territorial advantage, the home side couldn't breach the resolute Roosters defence.
The Roosters were first on the scoreboard after 21 minutes when Naufahu Whyte powered over next to the posts on the last tackle.
It took just five minutes for the Warriors to bounce back, with Leiataua getting on the outside of his opposite Mark Nawaqanitawase to plunge over.
Both sides had chances before the break, but at halftime the game was well and truly in the balance, the visitors up 6-4.
There was a scary moment for the Roosters involving Victor Radley midway through the first half.
The English international, returning after missing last week's massive win while in the concussion protocol following a collision with James Tedesco 13 minutes into the Roosters' season opener, lasted just five minutes longer this time before the independent doctor brought him from the field for a head injury assessment.
Radley had put his head in the wrong place while attempting to tackle Warriors man-mountain Marata Niukore, colliding with his hip, but he passed his HIA and returned to the field later that half.
Fellow Rooster Connor Watson wasn't so lucky, coming off after suffering a head knock on the stroke of halftime, before failing his HIA.
Teammate Spencer Leniu dislocated a little finger but continued on with gusto.
The Warriors were hit by the NRL's injury curse too, with veteran winger Roger Tuivasa-Sheck limping off with a hamstring injury midway through the second half after making a try-saving tackle on Dominic Young.
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