After carving out 26 attempts on goal, Dons did everything but score until Harrison got on the end of Jack Payne’s free-kick, prodding home his third goal of the season.
Here’s how we rated the players.
1. Craig MacGillivray - 7
A passenger for most of the game, barely even called upon to play out. Made two key saves though to keep Colchester at bay Photo: Jane Russell
2. Warren O'Hora - 7
Ensured Colchester were limited to precious little Photo: Jane Russell
3. Top Don: MJ Williams - 8
Showed what he can do at centre back. Marshalled his man out of the game, even had a few roams forwards too, acting as an extra man in midfield. A top drawer performance Photo: Jane Russell
4. Dean Lewington - 7
Got given the sponsor's man of the match prize on his landmark day. Solid as ever, rewarded with a clean-sheet and three points Photo: Jane Russell