Naruto can win this. Amaterasu/enton can be countered like it was at VoTE (since Naruto is friends with the Kyubi), or Naruto senses the pressure build-up and makes a kage bunshin right in front of him to block LoS. FRS obliterates him because Sasuke doesn't have the speed to dodge the attack or explosion radius. Naruto definitely wins Scenario 2.