The 2008 Australian Open winner had a 6-0, 6-1 second-round win over U.S. qualifier Jamie Hampton in 64 minutes on Thursday, two days after beating Argentina's Gisela Dulko by the same margin.
Sharapova did not play in any warmup events and spent nearly two weeks in Melbourne ahead of the season's first major while she rested an injured left ankle.
There was no indication of any problems with the ankle on Thursday, but the 24-year-old Russian wasn't really tested by No. 144-ranked Hampton, who has only ever won one match at a Grand Slam.
"It was more about getting my feet going ... worrying about myself," Sharapova said. "Yeah, started my preparations in the off-season a little late, took a bit of extra time in practice instead of rushing into a tournament."
She'll meet either Stephanie Dubois of Laval, Que., or 30th-seeded Angelique Kerber of Germany in the next round.
Seventh-seeded Vera Zvonareva, a two-time semifinalist at Melbourne Park, had a 6-1, 7-6 (3) over Lucie Hradecka. No. 21 Ana Ivanovic also advanced, beating Dutch player Michaella Krajicek 6-2, 6-3.
Sharapova is one of three former champions still in contention. Serena Williams was bidding to extend her winning streak to 16 matches at Melbourne Park when she played Barbora Zahlavova Strycova in the subsequent match on Rod Laver Arena. Williams won back-to-back titles in 2009 and '10 but missed last year's tournament due to injuries.
Defending champion Kim Clijsters is into the third round on the other half of the draw.
Top-ranked Caroline Wozniacki is aiming for her first major tile, and is one of four women in the draw who can finish the tournament at No. 1.
After her 6-1, 7-6 (4) second-round win over Anna Tatishvili on Wednesday, she asked how her boyfriend might be able to help.
She smiled, paused, then relayed some of the advice Rory McIlroy offered that helped him overcome similar pressure and win a golf major.
"Well, it's just about you can't really do anything about the past," Wozniacki said. "You just need to look forward. You have a tournament now, and you want to do the best you can. That's it.
"Then if it goes well, it's great. If not, you have the next one. It's like tennis."
McIlroy was considered a major golf talent on the cusp of a breakthrough when he blew a four-stroke lead and lost last year's Masters. He handled it with such humility that it didn't surprise anyone when he rebounded to win the U.S. Open two months later, when he was 22.
Wozniacki is into a third-round match against No. 31 Monica Niculescu. A win could put her on course for a quarter-final match against Clijsters, who routed Stephanie Foretz Gacon of France 6-0, 6-1.
Clijsters will face longtime friend Daniela Hantuchova in the third round, and a win there could set up a fourth-round match against French Open champion Li Na, a rematch of the 2011 Australian final.
Third-seeded Victoria Azarenka advanced in a night match with a 6-1, 6-0 win over Australian wild card Casey Dellacqua. Former top-ranked player Jelena Jankovic stayed alive in the draw after beating Chang Kai-chen 6-4, 6-2 and could be a fourth-round rival for Wozniacki.
On the men's side, No. 2 Rafael Nadal advanced without much trouble from his injured right knee or from German veteran Tommy Haas in a 6-4, 6-3, 6-4 win. Four-time champion Roger Federer didn't even need to pick up a racket because Andreas Beck withdrew from their second-round match.
The top-ranked American man bowed out when No. 8 Mardy Fish lost to Alejandro Falla of Colombia 7-6 (4), 6-3, 7-6 (6). But No. 16 John Isner survived a five-setter to beat former Wimbledon finalist David Nalbandian, who was enraged by an umpire who didn't allow him to challenge a disputed line call because he took too long to ask for a review.
No. 7 Tomas Berdych, 2009 U.S. Open champion Juan Martin del Potro and No. 18 Feliciano Lopez all advanced.
Andy Roddick was scheduled to play the last match Thursday against Lleyton Hewitt in a battle between two former No. 1-ranked players. Defending champion Novak Djokovic has an earlier centre court match against Santiago Giraldo. Andy Murray, who has lost the last two Australian Open finals, takes on Edourd Roger-Vasselin.