  We present G-band and Ca II H observations of NOAA AR 10930 obtained by
Hinode/SOT on 2006 December 6 covering an X6.5 flare. Local Correlation
Tracking (LCT) technique was applied to the foreshortening-corrected G-band
image series to acquire horizontal proper motions in this complex
beta-gamma-delta active region. With the continuous high quality, spatial and
temporal resolution G-band data, we not only confirm the rapid decay of outer
penumbrae and darkening of the central structure near the flaring neutral line,
but also unambiguously detect for the first time the enhancement of the sheared
Evershed flow (average horizontal flow speed increased from 330+-3.1 to
403+-4.6 m/s) along the neutral line right after the eruptive white-light
flare. Post-flare Ca II H images indicate that the originally fanning out field
lines at the two sides of the neutral line get connected. Since penumbral
structure and Evershed flow are closely related to photospheric magnetic
inclination or horizontal field strength, we interpret the rapid changes of
sunspot structure and surface flow as the result of flare-induced magnetic
restructuring down to the photosphere. The magnetic fields turn from fanning
out to inward connection causing outer penumbrae decay, meanwhile those near
the flaring neutral line become more horizontal leading to stronger Evershed
flow there. The inferred enhancement of horizontal magnetic field near the
neutral line is consistent with recent magnetic observations and theoretical
predictions of flare-invoked photospheric magnetic field change.
