DUBAI Wimbledon champion Goran Ivanisevic slumped to a 6-3 6-4 defeat by Nicolas Kiefer in a first round clash between two former winners of the Dubai Open on Monday.

Kiefer's victory over the seventh seeded Croat ended an 11-match losing streak for the German, who won four games in a row after losing his opening service game of the match.

Ivanisevic found his serving touch to fire down seven aces but Kiefer, the 2000 Dubai champion, held firm to take the first set.

Ivanisevic broke to lead 4-2 in the second but immediately dropped his own serve, receiving a code violation warning from the umpire after hitting a ball out of court and throwing his racquet, which landed on Kiefer's bag by his chair.

Looking increasing resigned to defeat, Ivanisevic over-ruled one call to award Kiefer an ace, and volleyed a backhand long to lose his serve again, before Kiefer served out for the match.