Board Thread:Naruto Discussions/@comment-12509038-20140421023306/@comment-1170104-20140430130738

He did not fight Gaara for those reasons. He fought Gaara, because he was ordered to capture/kill him by Genma. Also Sasuke wanted to prove his own strength and limitations. Like Shino said, he wanted to finish his fight. His teammates were nowhere in sight when he battled Gaara.