Serbia beat Australia at the Hopman Cup despite world number one Novak Djokovic suffering a shock defeat at the hands of Bernard Tomic on Wednesday.
It was Djokovic's first defeat on Australian soil since 2010, with the Serbian aiming for his third straight Australian Open title in Melbourne later this month.
With the 20-year-old Tomic showing the undoubted talent he has only displayed in flashes so far in his short career, a rusty Djokovic was broken in the ninth game of each set, losing 6-4, 6-4.
Tomic applied great pressure to the Djokovic serve throughout, holding 13 break points during the match.
He also hit 25 winners, to just 12 from Djokovic.
It was the first time the Serbian had been beaten by Tomic, ranked 52nd in the world, in four official meetings.
Djokovic, 25, dismissed the setback, having arrived in Perth only a few days ago after winning in Abu Dhabi.
"I knew I was coming here to Australia very late and it takes me time to get used to it," he said.
"I know I am not close to my maximum, but I expected that.
"I was always on the back foot and he was the better player."
Djokovic said he was fully aware of Tomic's talent, the Australian reaching a career-high ranking of 27 at June. Tomic was a quarter-finalist at Wimbledon in 2011 and made the fourth round at last year's Australian Open.
"He is right up there with the up-and-coming players, he is very talented," Djokovic said of Tomic.
"He knows the game well and tactically plays very well for someone his age.
"He definitely has the game."
Tomic said it was the best win of his career and a result that he needed to build on.
"I am still improving and I have got a lot more to improve," he said.
"This is a good sign and I have to continue to play like this."
Ana Ivanovic then levelled the Group A tie with a 6-2, 6-3 win over teenager Ashleigh Barty.
Serbia clinched the tie and remained unbeaten with a 6-4, 6-7 (8/10), 10-6 win in a match tiebreak in the mixed doubles.
Earlier on Wednesday, former French Open champion Francesca Schiavone showed her fighting qualities as Italy beat Germany 2-1.
Needing to win her singles match to keep Italy alive in the tie and the mixed teams tournament, the world number 35 was a set and a break down while battling stomach pain against little-known German Tajana Malek, but rallied determinedly to win in three sets.
Things were going to script when Schiavone won the first three games of the match, but the 112th-ranked German then won the next eight games in succession, before the Italian steadied to win 3-6, 6-3, 6-3.
Schiavone and Andreas Seppi then clinched the tie with a 6-4, 7-5 win over Tommy Haas and Malek in the mixed doubles.
Haas had given the Germans the lead in the tie with a hard-fought straight sets win over Seppi, 7-6 (7/3), 7-6 (9/7).
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