Much the better side throughout, Rochdale could and should have won by a wider margin and were denied in the second half by Mansfield keeper Carl Muggleton and the woodwork.
Having controlled the early stages Rochdale deservedly took the lead midway through the first half when Mocquet produced a pin-point cross that was greedily accepted by leading scorer Chris Dagnall for his ninth goal of the season.
With Rochdale completely on top Muggleton produced an excellent save to keep out a Glenn Murray header but was beaten just before the break when former Mansfield midfielder John Doolan rifled home a 20-yard free-kick.
Rochdale should have extended their lead through substitute Morike Sako but the giant Frenchman saw one effort saved by Muggleton and then, after a 40-yard run, saw his sweetly-struck effort rattle the upright.
Mansfield, in a poor run of form on the road, threatened only briefly during the game with leading scorer Richard Barker going close with a downward header.
It wasn't until the dying minutes that they managed an on-target effort through substitute Simon Brown, who saw his low drive comfortably saved by Rochdale keeper Matt Gilks.