Naturally after I commented she appears to have woken up a bit. I just saw that she was down 4-1 and losing the first few points on her serve there still when I posted. And to answer the question, I went ahead and looked since I was curious. I went through all of the open era women's Wimbledon winners, and there was one.... Graf in 1994 was the defending champ and lost in the first round. For the Men's side, Hewitt actually lost as defending champ in the first round in 2003. (Note, I was looking only at Wimbledon here)