But it was a brilliant hit by Koroibete on Chris Sandow to prevent a certain try two minutes later that proved to be the game's turning point.
The enigmatic halfback, who once again impressed for the Eels, juggled the ball over his head as he latched onto his own kick and chase, only to be ironed out by a Koroibete bell ringer just a metre in front of the posts.
With Benji Marshall becoming more influential as the game, the Tigers seized control and Utai added his second in the right corner, before Koroibete raced over for his first try.
He chalked up his second in the 56th minute before Moltzen waltzed over for his ninth of the season to ice a vital victory.
Marshall kicked a late field-goal to add some gloss to the victory before Koroibete scored twice more in the final three minutes.
Sheens slammed his side's defending and said they have to improve in their final four games where they face St George Illawarra, Canterbury, Sydney Roosters and Melbourne.
"It was pretty disappointing defensively, we fell away in the first half and we have some work to do there if we are to beat the four teams we have to play,'' Sheens said.
Skipper Robbie Farah concurred but said the second-half performance would give the side confidence going into the last month of the season.
"I guess we didn't want to tackle tonight and it was a good job they didn't either,'' Farah said of the Eels.
Caretaker coach Arthur bemoaned Parramatta's second-half fade out.
"We put ourselves in a position to win the game but we didn't because we didn't want to tough it out in defence,'' Arthur said.
"We were happy to play footy but right from the start you could see our contact wasn't good enough.''
- AAP