A novel dysprosium(III)-containing olytungstoarsenate, [{As-W9O33)(3)Dy-2(H2O)(4)W4O9(H2O)}(2)(NH2(CH2PO3)(2))](33-), comprising two identical subunits bridged by an organophosphonate ligand shows single-molecule-magnet (SMM) behavior. Magnetic studies reveal that this complex exhibits a butterfly-shaped hysteresis loop up to 8 K, and a thermally activated energy barrier of 101(5) K reached a breakthrough among all polyoxometalate-supported SMMs.