SYDNEY -- Novak Djokovic beat Rafael Nadal and then went back on court within an hour and won the deciding doubles encounter to secure Serbia's victory over Spain in the inaugural ATP Cup final.
Second-ranked Djokovic had a 6-2, 7-6 (4) win over No. 1 Nadal on Sunday night to level the final after Roberto Bautista Agut had given Spain a 1-0 lead by beating Dusan Lajovic 7-5, 6-1 in the first singles match.
After extending his lead to 29-26 in career head-to-heads with Nadal, plus his supremacy over the Spaniard on hard courts, Djokovic combined with Viktor Troicki for a 6-3, 6-4 win over Pablo Carreno Busta and Feliciano Lopez.
"I'll remember this experience for the rest of my life -- it's one of the nicest moments of my career," Djokovic said. "I've been very fortunately blessed, had an amazing career over the last 15 years, but playing for a team, playing for a country with some of my best friends is just -- you can't match that. It's too special."
He joked in an on-court TV interview that the team would fly home to Serbia to celebrate before the Australian Open, which starts a week from Monday, but decided the party should start in Sydney.
"There's a lot of Serbian people in Sydney," Djokovic said. "If you want to make a celebration, we're ready."
Nadal, who hasn't beaten Djokovic on a hard surface since the 2013 U.S. Open final, withdrew from the doubles, citing fatigue, saying he had confidence in his teammate Lopez, a four-time Davis Cup champion.
"I have been playing a lot of tennis the last couple of days. My level of energy is a little bit lower than usual, because I played long yesterday, very long before yesterday, very long in [Perth]," Nadal said. "So is a team decision, and we believe in our team. That's why we had success in the past."
After playing six singles matches and two doubles matches in 10 days -- on the west and east coasts of Australia -- less than two months after guiding Spain to the Davis Cup title in Madrid, Nadal urged the International Tennis Federation and the ATP to negotiate to form one world team championship.
"I think [ATP Cup] is a great competition, but at the same time -- I can't change my mind that two World Cups in one month is not real. So is not possible," he said. "So we need to find a way to fix it and we need to find a way to make a big deal with ITF and ATP to create a big World Team Cup competition, not two. I think that's a confusion for the spectators, and we need to be clear in our sport."
Spain's early lead put extra pressure on Djokovic, who has won a record seven Australian Open men's singles titles. He hadn't lost a singles match at the new 24-team tournament, and started out as if losing wasn't a consideration.
"I started off the match perfectly, really. Everything worked for me," he said. "Serve got me out of trouble in the second set."
He broke Nadal's serve in the opening game, which lasted eight minutes and included two requests from the umpire to the crowd to keep quiet during the service motion.
Djokovic held for a 2-0 lead, the game going to deuce, and then didn't concede a point on serve for his next three games, closing the set in 39 minutes with three straight aces.
Nadal, meanwhile, was struggling to hold, with Djokovic typically relentless with his returns. After Nadal was broken for the second time, in the seventh game, he went to the chair umpire in the changeover to complain about the noise during his service swing, and held his thumb up to the crowd as he walked back to his team zone.
The Spaniard found his range in the second set, though, conceding just a point in each of his first three service games. He had also had a huge opportunity to go up a break in the sixth game but was unable to convert five chances as Djokovic rallied from 0-40 to hold.
Djokovic then had two breakpoints in the 11th game, which would have given him the chance to serve for the match, but Nadal rallied from 15-40 to hold.
Djokovic had a nervy start to the tiebreaker, double-faulting to fall behind 2-1, but after his forehand clipped the net and landed in, he started to gain control. From 4-4, he won every point, starting the roll with a backhand winner down the line.
The 10,223-strong crowd at Ken Rosewall Arena was packed with Serbia supporters who waved their flags and chanted "Serbia, Serbia, Serbia," and Djokovic's nickname "Nole" throughout the final.
A little after 1 a.m. local time Monday, they were cheering for their champions.