Proton decay from odd-odd deformed nuclei is a long-standing unsolved problem. We present for the first time an exact solution using single particle Nilsson resonances. The lifetime is found to depend strongly on the single particle level occupied by the unpaired neutron, allowing a clear assignment of its Nilsson level. The emitters 112Cs, 140Ho, 150Lu, and 150Lu(m) are considered. The agreement with the experimental data is very good with deformations 0.1<beta<0.19 for 112Cs and -0.17<beta<-0.16 for the ground and isomeric states of 150Lu. In the case of 140Ho, two ranges of deformation 0.16<beta<0.28 and 0.28<beta<0.38 according to the neutron single particle level can describe the experimental half-life.