Parramatta lost influential halfback Mitchell Moses to concussion during the 27-8 qualifying final loss to Penrith in a blow to the Eels' hopes of avoiding four straight years of semi-final heartbreak.
Moses is now racing the clock to recover in time for next weekend's sudden-death semi, to be played against either Melbourne or Canberra.
The Eels have bowed out in the second week of the finals for the last three seasons but would have liked their chances to buck the trend when they booked a qualifying final berth against Penrith.
Parramatta have been responsible for two of the Panthers' four losses this year and are the only team to have defeated the reigning premiers when Nathan Cleary and Jarome Luai have played.
Beat the Panthers, and the Eels would lock in preliminary final tickets: the deepest they have travelled into finals in the nine years of Brad Arthur's coaching tenure.
But when Moses' head collected the hip of Viliame Kikau as he attempted to tackle the Panthers second-rower on the hour-mark, the Eels faction of the Penrith Park crowd held its collective breath.
Moses appeared to have been knocked out on impact but was eventually able to rise to his feet and leave the field. He played no further part in the contest.
The game had been a physical contest poised at 13-8 but the Panthers crossed for their third try just 15 seconds after Moses left the field, and then again in the following set.
Down 25-8, the Eels were rattled by the loss of Moses, committing five errors in the last quarter of the game, and did not have the stocks to close the gap on the Panthers.
What's more, the Eels may now have to contend without their creative architect next week, depending on when their semi-final is scheduled and how quickly Moses can recover.
Moses' opposite number put on a kicking masterclass, targeting Waqa Blake in Cleary's first game back from the five-week suspension he incurred the last time the Panthers played Parramatta.
The Eels' pack has been the envy of the competition this season and had the wood over the Panthers in the first half.
But the Panthers stifled the Parramatta offload game that haunted them in the sides' last two meetings and frustrated the Eels into a lacklustre second-half completion rate.
By fulltime, Parramatta had completed at just 66 per cent, compared to the 83 per cent completion rate of the Panthers, who are now only one win away from their third grand final appearance in as many years.
