The Indian pair maintained their unbeaten run to tame Australia's Alicia Molik and Peter Luczak in the mixed doubles encounter to pull off their first win in group 'A' of the Hopman Cup in Perth on Wednesday.
Justine Henin is likely to be favourite to win the Australian Open but Serena said she believes she could retain the trophy.
The Indian tennis contingent arrived in Doha for the Asian Games minus Leander Paes and Mahesh Bhupathi.
India takes on China in the opening match of the Asian Hopman Cup team tennis tournament.
Sania Mirza held on to 32nd place for the third consecutive week, while Leander Paes jumped four rungs to No 13 in the doubles ranking in the latest rankings.
Serena Williams is a year short of spending a quarter of a century as a professional player but the learning has never stopped for the 23-time Grand Slam winner.
Australian Open holder Djokovic will make his ATP Cup debut for Serbia against South Africa in Brisbane on Saturday while Nadal will lead Spain into action against Georgia in Perth on the same day.
Hosts Australia beat Russia 2-1 in the opening tie of the Hopman Cup.
The doubles star has confirmed for Chennai Open after missing the ATP event last year.
List of Australian Open men's singles champions since the event began in 1905 (Australian unless stated):
Reader Amit Modi sent us a picture of Sania Mirza from Perth, Australia.
Sania Mirza and Rohan Bopanna won the decisive mixed doubles to snatch a 2-1 victory in the Hopman Cup.
Tommy Robredo came from a set down to beat Mario Ancic and give Spain
The Davis Cupper, ranked 388, withdrew because of a wrist injury that has kept him out of action since August.
Sania Mirza and Rohan Bopanna continued with their blistering form as India thrashed Japan 3-0.
Thailand defeated the Philippines 2-1 in Group B match of the Asian Hopman Cup tournament.
The 28-year-old Australian pulled out of the first Grand Slam of the year because of injury.
The Indian tennis ace began the year at a career-best 31 on the WTA charts.
Summary of sports events and persons who made news on Wednesday
After a stomach injury cut short the last-leg of her season, Sania Mirza slipped two rungs to 32nd in the latest WTA Tour rankings.
Mark Philippoussis is in doubt for this month's Australian Open after pulling out of the Sydney International on Sunday with a muscle tear.
List of Australian Open women's singles champions since the event began in 1922 (Australian unless stated):
Plotting a path to the Australian Open has never been trickier or more uncertain. Even the best players are baffled about the best way to prepare for their annual trek Down Under.
Clijsters and Xavier Malisse gave Belgium a 2-0 winning lead over Slovakia in the Hopman Cup.
The world number two is doubtful for the the Australian Open starting next week.
He beat Jiri Novak to hand the United States victory over the Czech Republic in the Hopman Cup.
Clijsters says she hopes she has discovered the "magic formula" to beating the Williams sisters.
The world number two was on crutches after sustaining a bruised bone in her foot at the Hopman Cup in Perth earlier this month.
Lleyton Hewitt beat Slovakia's Karol Kucera to bring Australia level in their Hopman Cup tie.
The world number two was forced to hobble away from her Hopman Cup match against Alicia Molik.
Marat Safin paid the price for his later-than-scheduled arrival at the Hopman Cup as top seeds Russia suffered a shock defeat to Germany.
Nick Kyrgios and Bernard Tomic gave Australia an unwanted reputation as a breeding ground for tennis brats during a tempestuous 2015 and the pair will be firmly under the spotlight in front of home crowds at Melbourne Park. With former world number one Lleyton Hewitt set to retire and the last of his two grand slam titles at the 2002 Wimbledon championships a distant memory, Australia has long yearned for a new force in men's tennis to challenge at the majors. Tomic, 23, and Kyrgios, 20, have both been tagged as the future of the sport in the country but the excitement generated by their undeniable talent gave way to dismay last season as the pair hogged the headlines for all the wrong reasons.
List of Australian Open men's singles champions since the event began in 1905 (Australian unless stated):
Their friendship and camaraderie, they say, goes way beyond tennis but Sania Mirza and Rohan Bopanna are in no hurry to form a mixed doubles team in the coming season despite the speculation that they could be pairing up for India at the Olympic Games next year.
Coach Patrick Mouratoglou claimed Serena Williams' fitness had since gone up a notch and Margaret Court's all-time record of 24 Grand Slam singles titles may well be in peril at the Australian Open.
While knowing the limits of his body and full of praise for his team for being able to patch him up repeatedly, the 37-year-old admitted fortune has played a part in his longevity.
Agnieszka Radwanska and Andy Murray picked up morale-boosting victories in the Hopman Cup on Wednesday to keep their Australian Open preparations on track.
List of Australian Open women's singles champions since the event began in 1922 (Australian unless stated):
Roger Federer has paid a glowing tribute to Alexander Zverev, hailing the 20-year-old German as having the 'full package' of skills.
