The on-loan Albion right-winger set up one goal and scored the other, both in added time, as Bolton won 2-1 at Huddersfield.
Cozier-Dubbery has been turning in moments of magic in League One this season, including a brilliant late equaliser at Leyton Orient.
But this double contribution topped the lot as Bolton secured their first away win of the season.
The former Arsenal prospect said: “It’s amazing, a great feeling. I’m proud. I’m buzzing right now.”
Cozier-Duberry was on loan at Blackburn last term and is loving his latest stint in the North West.
He added: “The players and staff, like I always say, are so supportive and I am really enjoying it. I couldn’t ask for more.”
Huddersfield put two, occasionally even three, defenders on Cozier-Duberry and thought they had kept him quiet, although his precise pass set up a good chance in the first half.
But his inch-perfect cross was nodded in by Sam Dalby for the late leveller.
The lively winger then capped a fine performance by drilling in an even later winner after a quick counter-attack.