Mattingly only hit the front from long-time leader Nick Fothergill after round 16, and held off a late charge from teammate Kyle Mueller to stand alone atop the podium.
The Kyabam duo polled 17 and 16 votes respectively, while Tatura's Fothergill finished third on 15.
It was a benchmark the Bulldog reached after round 13 thanks to a roaring start to the year, but he was unable to add more votes in the final few rounds.
In all, 150 individual Goulburn Valley League players polled in the award, which is voted on by the News sports desk each week in a 3-2-1 format.
The Bombers dominated the voting throughout the season, with Brad Whitford (12 votes), Lachie Smith (12) and Pat Wearden (11) joining Mattingly and Mueller in the top 10.
Shepparton's Anthony Andronaco and Echuca's Angus Byrne also polled 12 votes, with fellow Murray Bombers Andrew Walker and Jobee Warde notching up 11.
Seymour's Jason Cole (10 votes), Benalla's Will Martiniello (10), Rochester's Nathan Marrone (nine), Mansfield's Tom German (eight), Shepparton Swans' Quade Johnstone (seven), Shepparton United duo David Gillespie and Shane Neaves (six), Mooroopna's Hudson Thomas (six) and Euroa trio Adam Giobbi, Jayden Gleeson and JD Hayes (five) led the voting for their respective outfits.