Maria Sharapova ruined Petra Martic's 24th birthday by recording a 6-4, 6-1 victory to advance to the second round of the Australian Open.
However, fifth-ranked Ana Ivanovic led a parade of women's seeds knocked out in the first round after the Serb was upset by doubles specialist Lucie Hradecka 1-6, 6-3, 6-2.
Sharapova will now meet compatriot Alexandra Panova in the second round after she beat Romania's Sorana Cirstea 7-5, 6-0.
Meanwhile, Ivanovic joined double grand slam winner Sveltana Kuznetsova (27th), Swiss teen Belinda Bencic (32nd) and Sabine Lisicki (28th) as seeded casualties in early first round action.
Ivanovic, a former Australian Open finalist, had roared through the first set in 21 minutes on Rod Laver Arena and looked set to follow third seed Simona Halep into the second round after the Romanian's 6-3, 6-2 win over Italy's Karen Knapp in the first game on the showcourt.
However, Hradecka, who played only three WTA level events in 2014, raced through the next two sets in just over an hour to send the Serb packing and set up a second-round encounter with Slovenia's Polona Hercog or China's Wang Qiang.
Bencic was hammered 6-2, 6-1 by Julia Goerges in just over an hour, while Kuznetsova, the 2004 US Open and 2009 French Open champion, lost 6-4, 6-2 to France's Caroline Garcia, and German Lisicki was beaten 4-6, 6-4, 6-2 by Kristina Mladenovic, also of France.