  We present the complete next-to-next-to-next-to-leading order short-distance
and bound-state QCD correction to the leptonic decay rate
Gamma(Upsilon(1S)->l+l-) of the lowest-lying spin-1 bottomonium state. The
perturbative QCD prediction is compared to the measurement
Gamma(Upsilon(1S)->e+e-)=1.340(18) keV.
