  For lensed galaxy SGAS J111020.0+645950.8 at redshift z=2.481, which is
magnified by a factor of 28 +- 8, we analyze the morphology of star formation
as traced by rest-frame ultraviolet emission, in both the highly-magnified
source plane, and in simulations of how this galaxy would appear without
lensing magnification. Were this galaxy not lensed but drawn from an HST deep
field, we would conclude that almost all its star formation arises from an
exponential disk (S\'ersic index of 1.0 +- 0.4) with an effective radius of r_e
= 2.7 +- 0.3 kpc measured from two-dimensional fitting to F606W using Galfit,
and r_e=1.9 +- 0.1 kpc measured by fitting a radial profile to F606W elliptical
isophotes. At the normal spatial resolution of the deep fields, there is no
sign of clumpy star formation within SGAS J111020.0+645950.8 . However, the
enhanced spatial resolution enabled by gravitational lensing tells a very
different story: much of the star formation arises in two dozen clumps with
sizes of r=30--50 pc spread across the 7 kpc length of the galaxy. The color
and spatial distribution of the diffuse component suggests that still smaller
clumps are unresolved. Despite this clumpy, messy morphology, the radial
profile is still well-characterized by an exponential profile. In this lensed
galaxy, stars are forming in complexes with sizes well below 100 pc; such sizes
are wholly unexplored by surveys of galaxy evolution at 1<z<3.
