Top seed Ons Jabeur won the final of the WTA tournament in Berlin on Sunday after Olympic champion Belinda Bencic was forced to retire after twisting her left ankle.
Bencic slipped at the end of the first set and despite receiving treatment, she eventually retired with Jabeur leading 6-3, 2-1.
Jabeur had raced into a 3-0 lead after just nine minutes before going on to win the third WTA title of her career after wins on grass last year in Birmingham and on clay in Madrid last month.
"From what I know of Belinda, she would have taken me to three sets today," said Jabeur, who wished her opponent a speedy recovery with Wimbledon due to start in a week's time.
"The most important thing for me is that she is okay."