The Collaborative International Dictionary of English v.0.48:

Expertly \Ex*pert"ly\, adv.
   In a skillful or dexterous manner; adroitly; with readiness
   and accuracy.
   [1913 Webster]

WordNet (r) 3.0 (2006):

expertly
    adv 1: in an expert manner; "he repaired the TV set expertly"
           [syn: expertly, like an expert] [ant: amateurishly]

Moby Thesaurus II by Grady Ward, 1.0:

33 Moby Thesaurus words for "expertly":
   ably, adeptly, adroitly, agilely, aptly, artfully, artistically,
   brilliantly, capably, cleverly, competently, cunningly, deftly,
   dexterously, dextrously, efficiently, excellently, featly, handily,
   ingeniously, masterfully, neatly, nimbly, proficiently,
   resourcefully, skillfully, spryly, superbly, well,
   with consummate skill, with finesse, with genius, with skill