The Cats, up against the ladder leader, knocked off Seymour in a heart-stopping four-point triumph to seal their first away win of the Goulburn Valley League season.
And what an opponent to do it against.
The incredible 10.10 (70) to 10.6 (66) comeback victory keeps the Cats locked in sixth spot on the ladder.
Keelin Betson starred in his return from injury and was a consistent contributor across the four quarters.
Chris Nield booted three majors, while Matt Gorman and youngster Dom Gugliotti chipped in with great performances.
Young gun and Murray Bushranger Tom Brown (one goal) made his first senior appearance for the Cats, while Sam Ward also featured in the blue and white colours for the first time.
Mooroopna coach John Lamont said it was a day to remember for the club.
“It was a really positive day for the club,” Lamont said.
“We hadn't won an away game all season and we had a real focus on it before the game. We faced the hard truth, we knew we hadn't won on the road and we knew it was because we haven't been organised enough away from home.
“But within the first couple of minutes in the warm-up I knew we were switched on.
“And then you had our younger players, Tom and Sam both making their debuts, while Jed (Woods) played in his first win. It was a pity there were no supporters there, but it was still a great day for the club.”
Lamont highlighted his group's ability to not give up as one of the most pleasing aspects of the win.
“I was really pleased with the result. To do that against quality opposition and away from home was fantastic,” he said.
“Our ability to stick to the task and not go into our shell was what stood out the most. Just being able to hang in there and not roll over.
“The boys showed terrific character.”
For the Lions, Josh Alford was their best performer, while young forward Hudson Kaak was impressive with four majors.
Seymour — which has held the tag of premiership favourite for the majority of the season — has now suffered back-to-back losses.
But it is not panic stations yet for the Lions.
A growing injury list has hampered Seymour in recent matches and the COVID-19 restrictions have also impacted its selection of players.
The Lions get a chance to bounce back with another home match against Shepparton Swans this weekend, while Mooroopna heads home to tackle the reigning premier Kyabram.
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