Nah, I would say it started downhill for Tobi when he got legit shook by Kabuto. All it took was the sight of a coffin for his own dastardly plans to slowly fall apart.
I mean, he stumbled a bit and slowly began to climb back up before losing his grip once his mask fell apart.
That's why I liked Tobi.
He felt like he was in way over his head.
He wasn't super powerful, he just had a very unique and versatile defensive ability that gave him an edge, and he felt very knowledgeable about the world.
He felt mysterious and intimidating, but still felt like the main characters had a reasonable chance to beat him.