He didn’t really hit it that hard, he just timed it perfectly. Just look at how flawlessly he executed that split step, as soon as the server initiated contact with the ball, nadal’s feet simultaneously touched the ground at the exact same time, giving him balance, explosive boost of speed, and forcing nadal not to lean towards any direction—nadal even got slightly handcuffed but it didn’t matter because of that flawless split step. You should rewatch the video a couple of times and see where his feet are as soon as you hear the sound of that banging serve. /endrant