Melbourne: Novak Djokovic sailed into the fourth round of the Australian Open after his friend and countryman Viktor Troicki retired ill after losing the first set 6-2 on Friday.
After netting a shot to concede the set, Troicki approached the world number three, embraced him and called off the match after 39 minutes.
"Like any tennis player, you don`t wish to win like this," 2008 champion Djokovic said in a courtside interview.
"I knew before the match that he had a little trouble with his stomach. I know it`s the third round of a grand slam and he wanted to give 100 percent ... And he was not able."
Djokovic will next play the winner of Nicolas Almagro and Ivan Ljubicic.