We present new precision measurements of the {Psi}(2S) total and partial widths from excitation curves obtained in antiproton-proton annihilations by Fermilab experiment E835 at the Antiproton Accumulator in the year 2000. A new technique of complementary scans was developed to study narrow resonances with stochastically cooled antiproton beams. It relies on precise revolution-frequency and orbit-length measurements, while making the analysis of the excitation curve almost independent of machine lattice parameters. For the {Psi}(2S) meson, by studying the processes {bar p}p {yields} e{sup +}e{sup -} and {bar p}p {yields} J/{Psi} + X {yields} e{sup +}e{sup -} + X, we measure the width {Gamma} = 290 {+-} 25(sta) {+-} 4(sys) keV and the combination of partial widths {Gamma}{sub e{sup +}e{sup -}}{Gamma}{sub {bar p}p}/{Gamma} = 579 {+-} 38(sta) {+-} 36(sys) meV, which represent the most precise measurements to date.