A longstanding conjecture asserts that every finite non-abelian p-group has a non-inner automorphism of order p. In this paper, we settle the conjecture for a finite p-group G, p an odd prime, of nilpotence class n with exp(γn−1(G)) = p and |γn(G)| = p, where γn(G) is the nth term in the lower central series. As a consequence, we give a short, quite elementary and derivation free proof of the main result of Abdollahi et al. [J. Group Theory 17 (2014), 267-272], for the odd prime p.