Aside from on Rod Laver and Hisense Arenas, play was suspended during the middle of the day due to the heat policy kicking in, but before that Sharapova and Carla Suarez Navarro both played marathon women's second round matches in the middle of the 40-plus degree conditions.
Play was suspended on all but Rod Laver and Hisense Arenas where the rooves could be closed as the Melbourne heat soared past 40 degrees on Thursday, but plenty of action still took place both before that and indoors.
Sharapova was first up on Rod Laver Arena and started her match against the 44th-ranked Italian Karin Knapp strongly enough winning the first set.
However, Knapp has been ranked as high as No. 35 in her career and certainly has plenty of fighting qualities, and she put all that on show the rest of the match.
Knapp managed to win the second set to force a deciding third and with the Rod Laver Arena roof still open, both women sweltered through the next 18 games of the third set.
Eventually, in the 17th game of the third set Sharapova was able to break the serve of Knapp, and then the Russian world No. 3 held serve to win the match 6-3, 4-6, 10-8.
It was a narrow escape for the former world No. 1 and four-time Grand Slam winner and the 26-year-old will now face French 25th-seed Alize Cornet in the third round.
Another former world No. 1 Caroline Wozniacki then followed Sharapova onto Rod Laver Arena, and with the roof closed the conditions were vastly improved for her and American Christina McHale.
Wozniacki also needed three sets to advance to the third round of the Australian Open even after failing to drop a single game in the first set.
The 21-year-old American then dominated the second set just as much losing only the one game, but the Danish 10th-seed then came back to dominate the third set and win the match, 6-0, 1-6, 6-2.
Ukraine's Elina Svitolina and Australia's Olivia Rogowska then started things off on Hisense Arena on Thursday and the 47th-ranked Svitolina knocked out the 22-year-old local 6-4, 7-5.
With the roof closed on Hisense Arena, Polish world No. 5 Agnieszka Radwanska cruised through her first set against Belarusian Olga Govortsova and despite having a tougher time in the second, she comfortably won through to the third round, winning 6-0, 7-5.
Before play was suspended on Margaret Court Arena with the roof not yet operational, Alize Cornet did battle with Camila Giorgi and it was yet another three-set women's battle on Thursday.
Eventually the French 25th-seed prevailed over the 99th-ranked Italian 6-3, 4-6, 6-4 as she now prepares for her third round battle with Sharapova.
The hottest, toughest and longest contest of the day, though, took place out on Court 2 and lasted three hours and 10 minutes with no protection from the heat whatsoever for Spain's Carla Suarez Navarro and Kazakhstan's Galina Voskoboeva.
For much of a 14-game third set, the Spanish 16th-seed barely looked able to move and the heat even affected her 77th-ranked opponent to the point where she even forgot there would be no third set tie-break once it got to six-all.
Eventually, Suarez Navarro prevailed 7-6 (2), 3-6, 8-6 to win through to the third round where she will face on-fire Slovak Dominika Cibulkova.
Cibulkova scored a dominant victory on Thursday dropping just one game on her way into the third round thrashing Swiss Stefanie Voegele 6-0, 6-1.
Meanwhile out on Court 6, Garbine Muguruza also managed to win through to the third round before play was suspended when she beat Slovak 6-3, 6-3.
Romania's 11th-seed Simona Halep also managed to get a victory booked in during the heat of the day in Melbourne when she beat American Varvara Lepchenko 4-6, 6-0, 6-1.
The Australian Open of New Zealand's Marina Erakovic is out after losing in straight-sets to Kazakhstan's Zarina Diyas on Court 13, 6-4, 6-0.
Russian 29th-seed Anastasia Pavlyuchenkova also dropped just four games on her way to a second round victory beating Luxembourg's Mandy Minella 6-2, 6-2.
The night session on Rod Laver Arena got underway with the defending champion and former world No. 1 Victoria Azarenka in action against Czech Barbora Zahlavova Strycova.
The Belarusian had little trouble cruising into the third round as well winning 6-1, 6-4 and will now face Austrian Yvonne Meusburger in the third round.
American Sloane Stephens finished off play for the night on Hisense Arena with a hard fought three-set victory over Croatian Ajla Tomljanovic.
The 13th-seeded American 20-year-old lost the first set but bounced back to beat the 67th-ranked Croatian 3-6, 6-2, 7-5.
When play recommenced on Court 6 after the heat delay, Spain's Garbine Muguruza beat Slovak Anna Schmiedlova 6-3, 6-3 to advance to the third round where she will face
Then to close things out on Thursday night on Court 6 Serbian 33rd-seed Bojana Jovanovski was upset by the 49th-ranked Austrian Yvonne Meusburger, who won 3-6, 6-3, 6-2.
Another former world No. 1 was in action after play recommenced following the heat suspension and Serbia's No. 8 seed also cruised into the third round with a 6-2, 6-0 victory over Japan's Ayumi Morita.
Meanwhile on Court 20, Japan's Kurumi Nara beat Slovak 32nd-seed Magdalena Rybarikova 6-4, 6-3.
Jankovic and Nara will now play one another in the third round.