Belgrade - The Djokovic family will not enjoy any success at their home tournament this year.
With defending champion and top-ranked Novak Djokovic having pulled out of the event, his brother Marko lost in the first round to Italian Filippo Volandri on Monday.
Marko Djokovic, a 20-year-old wildcard entry, was broken four times and never forced a break point of his own before losing 6-3, 6-1 in one hour.
The tournament is organised by the Djokovic family, but Novak pulled out because of the recent death of his grandfather - a decision he called one of the hardest of his career.
In other first-round matches on Monday, Dusan Lajovic of Serbia defeated fellow wildcard entry Evgeny Donskoy of Russia 7-5, 6-4, and Ivan Dodig used six breaks of serve to overcome Adrian Ungur of Romania 6-2, 6-7 (4/7), 6-4.
Results on Monday from the Serbia Open on clay at Tennis Centre Novak (seedings in parentheses):
First RoundDusan Lajovic, Serbia, def. Evgeny Donskoy, Russia, 7-5, 6-4.
Ivan Dodig, Croatia, def. Adrian Ungur, Romania, 6-2, 6-7 (4/7), 6-4.
Filippo Volandri, Italy, def. Marko Djokovic, Serbia, 6-3, 6-1.