In [3] the authors introduced a {\em relative category} for a map that differ from the {\em sectional category} by just one. The relative category has specific properties (for instance a homotopy pushout does not increase it) which make it a convenient tool to study the sectional category. The question to know when secat equals relcat arises. We give here some sufficient conditions. Applications are given to the {\em topological complexity}, which is nothing but the sectional category of the diagonal.