A second-half goal from winger Aiden White was enough to earn Oldham a 1-0 win at Dagenham.
Striker Oumare Tounkara beat his marker and although his shot was blocked by Abu Ogogo, White was on the spot at the back post to smash past Chris Lewington in the 57th minute.
The home side struggled to create chances with midfielder Romain Vincelot going closest in each half.
The Latics always looked dangerous on the counter-attack and could have taken the lead before half-time when Cedric Evina played in White, but his touch let him down.
Daggers boss John Still threw on three substitutes late on to try to lift his side, but the impressive defensive pairing of Reuben Hazell and Jean-Yves M'voto stood up to everything aimed at them as the Latics held out.
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