Roddick defeats Djokovic

My Australian Open predictions are not going well so far. Andy Roddick upset Novak Djokovic in the quarterfinals earlier today. Though I'm glad to see Roddick win, I certainly didn't expect it. Djokovic is #3 in the world and the defending champ at this event. He took the first set off Roddick in a tiebreaker but dropped the following two. In the fourth set, he started cramping due to the severe heat and retired, unable to continue playing. An unfortunate way to end the match, but I'm sure Roddick is just as glad to advance to the semis. In the other QF, Federer beat Juan Martin del Potro 6-3, 6-0, 6-0. I don't know whether del Potro played horribly or Federer played amazingly well, but I suspect a little bit of both. That's just an incredible score. So, Federer will take on Roddick in the semis. The other quarterfinal matches are tomorrow. I'd guess that both Nadal and Tsonga will win, but my predicting ability is not the best.