masterful(s = adj.all) consummate, masterly, virtuoso - having or revealing supreme mastery or skill; "a consummate artist"; "consummate skill"; "a masterful speaker"; "masterful technique"; "a masterly performance of the sonata"; "a virtuoso performance"

1.  Inclined to play the master; domineering; imperious; arbitrary. Dryden. [1913 Webster]

2.  Having the skill or power of a master; indicating or expressing power or mastery. [1913 Webster]
"His masterful, pale face." [1913 Webster]

masterful, adj.
1 imperious, domineering.
2 masterly.

Usage:
Normally used of a person, whereas masterly is used of achievements, abilities, etc.

Derivative:
masterfully adv. masterfulness n.