Former winners Roger Federer and Maria Sharapova also progressed smoothly on a day of high temperatures at Melbourne Park, where one ballboy felt faint and had to be helped from the court.
Djokovic's main opponent was the 35 Celsius (95 Fahrenheit) heat as, cooling himself with ice vests on the change-overs, the top seed dispatched Korean rising star Chung Hyeon 6-3, 6-2, 6-4.
"You try to stay composed, not get carried away by heat, get distracted," said the Serb, who was forced out of the 2009 quarter-finals as he struggled with the heat.
Williams also made a positive return to competitive tennis, four months after a heartbreaking defeat in the US Open semi-finals ended her bid for a rare calendar-year Grand Slam.
Showing no discomfort from the swollen knee which forced her out of this month's Hopman Cup mixed-team tournament, Williams toughed it out 6-4, 7-5 against Italy's Camila Giorgi.
"I haven't played a competitive match in a really long time so it was good for me to come out here and get through it," Williams said. "I was able to stay in it and stay calm and that is what matters most."
Federer was also untroubled in his 6-2, 6-1, 6-2 win over Georgia's Nicoloz Basilashvili as he continued his quest for a record-extending 18th Grand Slam title.
Sharapova, the women's winner in 2008, beat Japan's Nao Hibino 6-1, 6-3 in just 73 minutes in her first match of the year after a forearm injury forced her out of the Brisbane International.
"I'm feeling really good, which is a positive. I'm just happy to finish off today and be able to get ready for the next one," said the Russian.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
