Five-time champion Venus Williams suffered a shock 6-2, 6-3 defeat against unseeded Bulgarian Tsvetana Pironkova in the quarter-finals at Wimbledon today. Not since Jelena Jankovic defeated Williams in the third round in 2006 had Venus failed to reach the women's singles final but the American second seed was completely out-played by Pironkova, the world number 82, in the most remarkable result of this year's Championships.