Davenport had lost just once since returning to tournament play last summer following the birth of her son but was out-matched by Sharapova, last year's Australian Open runner-up. Sharapova jumped out to a 5-0 lead and fired off 26 winners in collecting a 6-1, 6-3 victory over Davenport.
Sharapova's fellow 2007 Australian Open finalist, Serena Williams, also was a straight-set winner Wednesday, stopping Meng Yung, 6-3, 6-1, and is 25-1 at the Australian Open since 2003.
World No. 1 Justine Henin ran her match winning streak to 30 with a 6-1, 7-5 win over Olga Poutchkova. Third-seeded Jelena Jankovic battled through a second set that took move than an hour before finishing off a 6-2, 7-5 win over Edina Gallovits.
There were a trio of upsets in the second tier of seeded players with Aravane Rezai eliminating 13th-seeded Tatiana Golovin, 6-3, 3-6, 6-3; local favorite Casey Dellacqua beating No. 15-seeded Patty Schnyder, 4-6, 7-5, 8-6; and Su-Wei Hsieh upsetting 19th-seeded Sybille Bammer.
Also Wednesday, 11-seeded Elena Dementieva overcame Anabel Medina Garrigues, 5-7, 6-2, 6-3; 12th-seeded Nicole Vaidisova beat Alicia Molik, 6-2, 6-3; No. 17-seeded Shahar Peer handled Jessica Moore, 6-0, 7-5; 18th-seeded Amelie Mauresmo slipped past Yaroslava Shvedova, 6-4, 7-6 (7-5); No. 25 Francesca Schiavone beat Angelique Kerber, 6-2, 6-3; 26th-seeded Victoria Azarenka swept past Sandra Kloesel, 6-1, 6-1; and 30th-seeded Virginie Razzano escaped Flavia Pennetta, 6-2, 5-7, 6-3.