Turbulence is significantly reduced in a tokamak plasma as a result of neon seeding of an L-mode discharge. Correspondingly, confinement is improved and cross-field ion thermal transport reduced. Fully saturated turbulence in the range 0.1</=k( perpendicular)rho(s)</=0. 6 is measured at rho = 0.7 and exhibits a factor of 5 reduction in total power after neon injection, with almost complete suppression for k( perpendicular)rho(s)>0.35. These observations are consistent with a reduction in the calculated linear growth rate for k( perpendicular)rho(s)>0.5 and an increase in the measured ExB flow shearing rate.