After two seasons of finishing with Dagenham in mid-table, Blackett played a part in the Daggers' promotion-winning campaign of 2006–07, but was sold to Peterborough United in the January transfer window, again alongside Mackail-Smith.
For two consecutive seasons, Blackett helped Dagenham finish mid-table, but played a crucial role in their promotion-winning season of 2006–07. However, he was subsequently transferred to Peterborough United in the January transfer period, accompanied by Mackail-Smith.