  Background: Proton-induced {\alpha}-knockout reactions empower direct
experimental manifestations of {\alpha}-clustering in nuclei. This is obtained
by relating the theoretical descriptions of clustering states with experimental
reaction observables. It is desired to introduce microscopic structure models
into the theoretical frameworks for {\alpha}-knockout reactions.
  Purpose: Our goal is to probe the {\alpha}-clustering in $^{10}$Be nucleus by
proton-induced {\alpha}-knockout reaction observables.
  Method: We adopt an extended version of the Tohsaki-Horiuchi-Schuck-R\"opke
(THSR) wave function of $^{10}$Be and integrate it with the distorted wave
impulse approximation (DWIA) framework for the calculation of (p,p{\alpha})
knockout reactions.
  Results: We make the first calculation for the $^{10}$Be(p,p{\alpha})$^{6}$He
reaction at 250 MeV implementing a microscopic {\alpha}-cluster wave function
and predict the triple differential cross sections (TDX). Furthermore, by
constructing artificial states of the target nucleus $^{10}$Be with compact or
dilute spatial distributions, the TDX is found to be highly sensitive to the
extent of clustering in the target nuclei.
  Conclusions: These results provide reliable manifestation of the
{\alpha}-clustering in $^{10}$Be.
