It was the second loss in three games for the Tigers, who are now 14-5 with one regular-season game remaining.
Darien upped its record to 15-2-2 with the victory.
Cam McGuire had two goals for Ridgefield. Henry Gough added the other goal.
Chris Morrow assisted on all three goals for the Tigers.
Ridgefield will close the regular season Wednesday against Trumbull before taking part in the FCIAC playoffs, which start Friday.