Not sure whether he is the only one, but when Goran Ivanisevic won Wimbledon in 2001 he was a wildcard.
Goran Ivanišević of Croatia.
2 - us open 2001 and Wimbledon 2002
Venus Williams beat Justine Henin 6-1 3-6 6-0 in the 2001 women's final.
Goran Ivanisevic notched up 212 aces during Wimbledon 2001.
Serena Williams has won the Wimbledon Ladies' Singles Championship twice in 2002 and 2003 with both wins coming against sister, Venus. However, the Williams sisters have played each other in the Wimbledon Championship final 3 time previous to 2009 (2002, 2003, and 2008). Defending-champion Venus Williams has won the Wimbledon Ladies' Singles Championship 5 times (2000, 2001, 2005, 2007 and 2008). Together, they have won the Wimbledon Ladies' Doubles Championship 3 times (2000, 2002, and 2008).
Goran Ivanišević (basic ASCII = Ivanisevic) was the Men's Champion at Wimbledon, 2001, having lost the championship four times previously. He is from Croatia.