There was real intensity from the outset and, once the shackles were off, plenty of flair to go with it. The forwards - led by Ben Matulino and a revitalised Jacob Lillyman - set the tone in the first 10 minutes with some thunderous hits and the Parramatta pack lost their edge after that.
They weren't helped by a run of misfortune. Nathan Peats and Tepai Moeroa both looked wobbly after getting their heads caught in the wrong place and Brad Takairangi limped away from a full-blooded front-on Thomas Leuluai tackle.
The first 20 minutes were the Warriors' best start to a match in an age. They scored three tries, could have had a few more and didn't make a single error nor concede a penalty. As Parramatta coach Brad Arthur ruefully pointed out, his team had possession for only two of the first 13 sets in the match.
Ryan Hoffman got things rolling with his third try in three matches - who knew the Warriors had purchased a try-scoring machine from the Storm? - scampering over from dummy-half through three defenders in the fifth minute. Five minutes later, Solomone Kata scored his second try in a week, first to a well-placed Chad Townsend kick. The try of the half followed soon afterwards, a burst up the middle by Leuluai, who sent Tui Lolohea in under the posts.
When Manu Vatuvei scored the Warriors fourth try - after Townsend ran off a Mannering offload - in just the 21st minute, it was party time at Mt Smart Stadium.
But they didn't go on with it, failing to make the most of great territory and field position, with fifth-tackle options again a problem as Shaun Johnson lost his range.
It was inevitable that the Eels would come back in the second half, and they took advantage of uncertainty in the Warriors' right-edge defence, accentuated after Tomkins left the field.
Brad Takairangi and Reece Robinson scored brilliant long-range tries and David Gower managed an opportunist try after a poor Jonathan Wright carry was dislodged by Anthony Watmough. It made for a nervy last 20 minutes - which looked utterly improbable in the first half - but the home side were good enough to hang on for the precious two points.
Warriors 29 (R.Hoffman, S.Kata 2, T.Lolohea, M.Vatuvei tries; S.Johnson 4 goals, field goal)
Eels 16 (B.Takairangi, D.Gower, R.Robinson tries; Robinson 2 goals).
HT: 22-0