It left the final of the inaugural team event finely poised at 1-1 after Spain's reliable Roberto Bautista Agut caned Dusan Lajovic 7-5, 6-1.
"Every time I get to play Rafa we get to play a lot of exciting points. There were some incredible exchanges today," said Djokovic. Djokovic, warming up for his bid to win an eighth Australian Open crown this month, went into the clash at Sydney's Ken Rosewall Arena leading their head-to-heads 28-26.The Serb had won nine of their past 12 contests and been dominant over the years on hard courts -- including a comfortable win against Nadal in the Australian Open final last year.
His driving groundstrokes and deft touches proved too much with Nadal's serve constantly under siege as Djokovic delivered a booming ace to wrap up the set.