But it didn't count.
First, here's the play:
Chiefs QB Matt Cassel dropped back to pass and looked deep for Baldwin, who had one-on-one coverage. Cassel winged it and it was slightly behind Baldwin but apparently that didn't matter. Baldwin reached behind (not around) the Broncos defender and pulled the ball into the defender's back. He fell to the ground still clutching the ball and, as they turned over, he yanked it away. It appeared this would have been called a catch if it weren't for the penalty that brought it back.
After the catch, Baldwin got up and was clearly excited by the play but learned shortly after that that the play was coming back.
I'll tell you, though, that got me excited about the future of Baldwin. The only question is whether Baldwin's was a better play than the one from Alabama WR Tyrone Prothro a few years ago.