?

Novak Djokovic of Serbia reacts during the ATP Cup semifinal match against Daniil Medvedev of Russia in Sydney, Australia, on Jan. 11, 2020. (Xinhua/Zhu Hongye)

SYDNEY, Jan. 11 (Xinhua) -- Serbia is through to the ATP Cup final, beating Russia in both singles matches here on Saturday, securing their place in the championship decider of the inaugural tournament.

The first singles match saw Dusan Lajovic beat Karen Khachanov, 7-5, 7-6 (1), setting up the world No. 2 Novak Djokovic to carry his team through to the finals.

However in a thrilling off script performance, it took Djokovic three sets to defeat fifth-ranked Daniil Medvedev 6-1, 5-7, 6-4.

As the second set slipped through his fingers, a visibly frustrated and exhausted Djokovic smashed his racquet to pieces on the court's surface.

"Yesterday I spent almost three hours on the court, today was pretty similar -- lot's of rallies, probably more rallies than yesterday's match and it was very exhausting," Djokovic said in a post match interview.

The Serb heaped praise on his opponent who despite losing the match can hold his head high for having squeezed every inch out of the reigning master.

"Daniil Medvedev is one of the best players in the world and today he showed why. He's very difficult to break from the baseline, very tall, he's got a good serve and this was the greatest challenge I've had so far this year," Djokovic said.

Serbia will meet either Spain or Australia in the final depending on who wins Saturday evening's match-up.