Sr 2 RuO 4 has been under intensive scrutiny over the past years after new NMR measurements unveiled that the superconducting state might be spin singlet. One of the best order parameter candidates in light of these new experiments is a chiral state with E g symmetry. This order parameter, with a horizontal nodal line, has been overlooked given the strong two-dimensional character of the normal state electronic structure. Recently, a phenomenological proposal based on local interactions showed that an even-parity orbital-antisymmetric spin-triplet (OAST) chiral state can be stable in Sr 2 RuO 4 once momentum-dependent spin-orbit coupling is properly taken into account. Here we discuss the origin of the nodes and dips in this order parameter as inherited from the normal state Hamiltonian, showing that a nodal gap can emerge out of purely local interactions and connect the presence of nodes with the superconducting fitness measure.