Van Rijthoven had won the first set in the tiebreak. In the second set, the 25-year-old Dutchman led 2-1 in games when he had to retire.
The tennis player has had a successful grass season. He won the Rosmalen grass tournament and reached the fourth round at Wimbledon. In it he lost to the Serb Novak Djokovic. Van Rijthoven lost last week in Newport in the first round to American Mitchell Krueger. In the world ranking of last Monday, Van Rijthoven is in place 101.