NRLW heavyweights Brisbane will miss the finals series for the first time in the competition's history after a 28-16 loss to Parramatta, who have surged from the bottom of the table to the play-offs.
Brisbane won the first three NRLW premierships but finished the season with 1-4 record to complete a fall from grace that started with their early exit from last year's finals.
Heading into the last round, the Broncos, Gold Coast and Parramatta all had chances to clinch fourth place and a finals spot.
The Eels were the only winless team of the three but by muscling up to beat the Broncos by more than six points were able to leapfrog the Queensland sides on points differential.
Forwards Kennedy Cherrington and Simaima Taufa spearheaded the team's physical effort, running for more than 250 metres each and scoring late tries that confirmed the most memorable win of Parramatta's short NRLW history.
"The performance was something I'm really proud of and something I'll remember for as long as I stay in footy," Eels coach Dean Widders said.
Both of the Eels' captains, Taufa and centre Tiana Penitani appear in doubt for next week's semi-finals with leg injuries, however.
"We'll have some assessment to do on everyone this week," Widders said.
"There are some tough injuries there. It's getting to that point in the season.
Broncos coach Kelvin Wright said Brisbane failed to meet the standards of their NRLW rivals this year as he lamented their poor discipline on Sunday.
"I thought today we just put ourselves under too much pressure right from the start of the game with the errors that we were giving up," he said.
Parramatta enjoyed the bulk of field position and possession but could not turn pressure into points early in the second half.
When Ali Brigginshaw stood up to mastermind a comeback and draw the Broncos level at 16-16, the game threatened to slip from the Eels' grasp.
But Taufa burst over to restore the Eels' six-point lead with nine minutes to play, before partner-in-crime Cherrington sealed the result on the right.
The victory helped the Eels exorcise their demons from last year, when a last-round loss to the Broncos ruled them out of the play-offs.