masterfully

from WordNet (r) 3.0 (2006)

masterfully
    adv 1: in a skillfully masterful manner; with the skill of a
           master; "the young boy played the violin sonata
           masterfully"

from The Collaborative International Dictionary of English v.0.48

Masterfully \Mas"ter*ful*ly\, adv.
   In a masterful manner; imperiously.
   [1913 Webster]

         A lawless and rebellious man who held lands masterfully
         and in high contempt of the royal authority.
                                                  --Macaulay.
   [1913 Webster]

from Moby Thesaurus II by Grady Ward, 1.0

43 Moby Thesaurus words for "masterfully":
      ably, adeptly, adroitly, agilely, aptly, arbitrarily, artfully,
      artistically, autocratically, brilliantly, capably, cleverly,
      competently, cunningly, deftly, despotically, dexterously,
      dextrously, dictatorially, efficiently, excellently, expertly,
      featly, handily, high-handedly, imperiously, ingeniously,
      magisterially, neatly, nimbly, overbearingly, peremptorily,
      proficiently, resourcefully, skillfully, spryly, superbly,
      tyrannically, well, with consummate skill, with finesse,
      with genius, with skill