  We consider a gauge inflation model in the simplest orbifold M4 x S1/Z2 with
the minimal non-Abelian SU(2) hidden sector gauge symmetry. The inflaton
potential is fully radiatively generated solely by gauge self-interactions.
Following the virtue of gauge inflation idea, the inflaton, a part of the five
dimensional gauge boson, is automatically protected by the gauge symmetry and
its potential is stable against quantum corrections. We show that the model
perfectly fits the recent cosmological observations, including the recent WMAP
5-year data, in a wide range of the model parameters. In the perturbative
regime of gauge interactions (g_{4D} <= 1/(2pi R M_P)) with the moderately
compactified radius (10 <= R M_P <= 100) the anticipated magnitude of the
curvature perturbation power spectrum and the value of the corresponding
spectral index are in perfect agreement with the recent observations. The model
also predicts a large fraction of the gravitational waves, negligible
non-Gaussianity, and high enough reheating temperature.
