Riker soon becomes very comfortable on the Enterprise , many times refusing offers of his own command . On part 1-2 on the episode `` The Best of Both Worlds '' Riker takes command on the Enterprise and orders Jean-Luc Picard rescued . In two-parter `` The Best of Both Worlds '' Riker takes command of the Enterprise assuming the rank of Captain through a field promotion and orchestrates Picard 's rescue .