Star five-eighth Kieran Foran's influence was again to the fore as the Warriors made it two NRL wins in a row by holding out Parramatta 22-10 in Auckland.
Facing the club he left prematurely in the middle of last season to deal with personal issues, Foran set up two of the Warriors' four tries.
It was his big break and pass in the 62nd minute that sent winger Ken Maumalo over for the score that pushed the home side out to a 20-10 lead after the Eels had dominated after halftime.
After a quiet start in which he didn't touch the ball until the 14th minute, Foran also produced the deft pass in the 32nd minute that sent lock Simon Mannering across for the Warriors' go-ahead try.
The win on Sunday lifted the Warriors to 3-3 for the season, but the loss was the Eels' fourth in a row after starting the year with two victories.
Parramatta opened the scoring midway through the opening half, back-to-back penalties setting up field position for lock Nathan Brown to dot down under the posts.
But the Warriors turned the match around with three tries in 10 minutes.
Second rower Bodene Thompson got the first from a sixth-tackle scramble, before Mannering scored off Foran's slick intrusion.
Thompson crossed again five minutes from halftime to hand the home side a 16-6 lead.
The Eels narrowed the gap early in the second half, second rower Manu Ma'u's offload with three tacklers on him keeping the ball alive for winger Josh Hoffman to score.
Five-eighth Corey Norman then touched down, but the Warriors got a reprieve with the try rubbed out for obstruction.
Foran's bust for Maumalo's try gave the home side breathing room to close out the game.