Technically, the second section of this song is really a very slow Salsa. It has all of the elements of Salsa, except for the tempo. The accent you hear on the 4&1 is the conga drum, which is present in Cha Cha, Rumba, Mambo, and Salsa.
Still, I wouldn't argue with you that it has a sort of a Cha Cha flavor. Then again, I wouldn't argue with any other interpretation, either... Rumba, Salsa, or Cha Cha. The second section is somewhat ambiguous, and I can see how someone might listen to it and hear any of those three dances (or maybe even Mambo, though it's a bit more of a stretch).
For simplicity's sake, I just used the Rumba interpretation for section two. It's not unreasonable... American style Rumba is alot more rhythmical than its International counterpart. But I do admit that this interpretation doesn't acknowledge the very disctinct rhythmical difference between sections.
Sincerely,
Jonathan Atkinson, webmaster