Above: video of Bryce Harper taking Livan Hernandez deep on Sunday night baseball. Destroyed that baseball. Here's Harper on Livo, via Nationals Journal:
"I was just looking for something I could drive. Livo throws really slow. You’re going to have wait back and try to get something up that you can drive out of the park or drive up the middle or the left side. He left something up, and I got it."
(Bryce Harper, via Nationals Journal, 5/28/2012)
And here's what it looked like when Livo baffled Harper with some 63 MPH junk in the sixth. Strike 3. Really slow: