Complex sentence: Sasuke flees this onslaught and activates his Cursed Seal of Heaven to Level One, but Naruto extends his claws to grab Sasuke and strikes him solidly with the left Chakra hand.
Split into simpler sentences: Sasuke flees this onslaught, but and activates his Cursed Seal of Heaven to Level One. But Naruto extends his claws to grab Sasuke and beats him with the left Chakra hand.