1) Toat 1) With the skill of a master 
• (adv.) In a masterful manner; imperiously.
Mas'ter·ful·ly adverb In a masterful manner; imperiously. « A lawless and rebellious man who held lands masterfully and in high contempt of the royal authority.» Macaulay. 
[adv] - in a skillfully masterful manner 2. [adv] - in a domineering and masterful manner
masterfully 1. In a domineering and masterful manner. 2. In a skillfully masterful manner; with the skill of a master.
adverb in a domineering and masterful manner; `his gaze held hers masterfully`