French duo Gael Monfils and Benoit Paire, both in the top 25, led their country to a 2-1 Group "A" win over Chile, while Argentina scraped past Poland by the same score. Serbia leads Group A with two wins.
"We love playing for our country", Djokovic said in his on-court interview.
"It was phenomenal. I mean, I didn't expect the Serbs to be honest, so many of them stay all the way through and basically spend a Christmas day with us after midnight, which is awesome, "said Djokovic". "Thanks to the people for staying to nearly 1 a.m.to support us". He is a great fighter and a great friend of mine.
"The inordinate loss of people, wildlife, stock, homes, schools and businesses is going to require an extraordinarily widespread effort to get these families and communities back on their feet", Tiley said.
Nadal has often struggled with injury at this time of year, but he has barely stopped this time around after leading Spain to Davis Cup glory in November.
Spain and Japan have both won their opening two matches and they know victory in Perth will mean they guarantee qualification for the final eight on Thursday in Sydney. "Everything was too short", said Nadal. "I played a very solid match, my serve worked better than the first day", Nadal said.
"Honestly, I think that deep down he is not such a bad guy", Djokovic said.
Roberto Bautista Agut defeated Franco Roncadelli 6-1, 6-2.
The six group winners and the two best runners-up qualify for the quarter-finals.
Hubert Hurkacz beat Borna Coric 6-2, 6-2 to split the singles results, but Croatia pair Ivan Dodig and Nikola Mektic clinched the encounter with a 6-2, 6-1 win in the doubles over Hurkacz and Lukasz Kubot.
The two-time Grand Slam champion and former number 1 in the world took more than two hours and had 16 aces to beat Saqqari.
An important stage of this contest was when Djokovic won 5 consecutive games in the 2 set to change the scoreline from 0-1 to 5-1. In the second round, Keys meets local favorite Samantha Stosur.
Japan followed up its 3-0 sweep against Uruguay with a win over Georgia, with Go Soeda beating Aleksandre Metreveli 4-6, 6-3, 6-2 and Yoshihito Nishioka beating Nikoloz Basilashvili 6-2, 6-3.
They said play would not have been possible in the Australian capital which has been choked by smoke, with the tournament now due to start Monday at Bendigo in Victoria state.
Anderson's win clinched the tie for South Africa following Lloyd Harris's 6-4, 6-4 victory over Nicolas Jarry.
The 30-year-old Frenchman, who is a holder of three ATP Tour singles titles, already served for the match at 5-4 in the second set, but then started a series of unforced errors that brought his Serbian opponent back into play.