We evaluate three meson doorway mechanisms for nucleon-antinucleon annihila
tion at rest for the first time. Detailed results are presented for the fin
al state phi pi(0) originating from the S-3(1) initial state and for the ph
i rho channel originating from S-1(0). The results presented also include t
he improved contributions from two meson doorway states and from the tree d
iagrams. For all the channels considered a consistent explanation of large
and small OZI violations emerges.