Halle - Newly-crowned French Open champion Rafael Nadal's start to the grasscourt season at Halle was cut short when the top seed crashed out in the quarterfinal to Germany's Philipp Kohlschreiber.
Kohlschreiber, ranked 28 in the world and defending champion, notched up his first-ever victory over Nadal in nine encounters, winning 6-3, 6-4.
The German will now play the winner of the match between Czech ace Tomas Berdych and Germany's injury-prone former world No 2 Tommy Haas.
Nadal, who captured a record seventh Roland Garros title on Monday, suffered an even worse result when he last played in Halle seven years ago, losing in the first round to Alexander Waske.
This time around, Nadal was in difficulty from his first service game and was quickly 2-0 down, Kohlschreiber going on to wrap the first game up in little more than 30 minutes.
After saving two breaks in the opening game of the second set, Nadal then missed the chance to break the German three times on his serve in the fourth game, and Kohlschreiber kept his nerve to beat the Spaniard comfortably.