SYDNEY, Jan. 13 -- Novak Djokovic has extended his supremacy on hardcourts against Rafael Nadal to force a deciding doubles encounter for the inaugural ATP Cup.

Second-ranked Djokivic leveled the final for Serbia with a 6-2, 7-6 (4) win over top-ranked Nadal on Sunday night, increasing his lead to 29-26 in their career head-to-heads. Nadal hasn't beaten Djokovic on a hard surface since the 2013 U.S. Open final.

The plan was for the world's two top-ranked players to go at it again in the doubles, but Nadal withdrew from Spain's combination and was replaced by Feliciano Lopez.

Roberto Bautista Agut had given Spain a 1-0 lead, and maintained his unbeaten streak at the ATP Cup, with a 7-5, 6-1 win in over Dusan Lajovic in the first singles m...