Novak Djokovic advanced to the Serbia Open final after Janko Tipsarevic withdrew from the all-Serb semifinal on Saturday because of a thigh injury.
The Australian Open champion will play either Feliciano Lopez of Spain or Filippo Volandri of Italy on Sunday.
Djokovic defeated Blaz Kavcic of Slovenia on Friday for his 26th consecutive victory without defeat in 2011. It is the best start to an ATP tour season, topping Ivan Lendl's record of 25-0 in 1986.
Djokovic has won four tournament titles in 2011 and unseated Roger Federer, the last man to beat him, for the No. 2 ranking.