A lesson to live by, folks -- don't mess with Hayden Panettiere. The indestructible cheerleader almost self-destructed on the Emmys red carpet last week, according to TV Guide!

Here's what went down: Hayden threatened to "kill" an Us Weekly reporter over their coverage of her split with Stephen Colletti. But right before Hayden threw down, her flack grabbed her and said, "Not on the red carpet." (Had this happened a month ago, Hayden would've landed on our list of The 10 Biggest Celeb Breakdowns!)

Pretty typical that the most exciting event of the Emmys happened on the red carpet. And on a side note, please don't try to kill us, Hayden!