Wozniacki beat Rodionova 6-2, 6-1, saving all three of the break points she faced. She claimed 65 percent of the points on serve. Her big advantage was on Rodionova's second serve. Wozniacki won 15-of-21 points in those situations.
Third-seeded Victoria Azarenka was even more impressive, taking out Heather Watson 6-1, 6-0 in 67 minutes. Azarenka finished off six of her 10 break-point chances.
No. 5-seeded Li Na defeated Ksenia Pervak 6-3, 6-1 and eighth-seeded Agnieszka Radwanska escaped a challenge from Bethanie Mattek-Sands 6-7 (10-12), 6-4, 6-2.
Tenth-seeded Francesca Schiavone was a 6-1, 6-3 winner over Laura Pous-Tio and Kim Clijsters, the 11th seed, opened defense of her Australian Open title with a 7-5, 6-1 win over Maria Joao Koehler. No. 13 Jelena Jankovic advanced with a 6-2, 6-0 rout of Laura Robson and 16th-seeded Peng Shuai beat Aravane Rezai 6-3, 6-4.
Three seeded women's players dropped opening-day matches. Qualifier Nina Bratchikova ousted 19th-seeded Flavia Pennetta 6-3, 1-6, 6-2; Christina McHale eliminated 24th-seeded Lucie Safarova 6-2, 6-4; and Galina Voskoboeva was a 7-5, 6-2 winner over 28th-seeded Yanina Wickmayer.
No. 32 Petra Cetkovska.
Qualifiers Chang Kai-Chen and Paula Ormaechea won as did wild-card entrants Casey Dellacqua and Olivia Rogowska.
Also moving into the second round were Mona Barthel, Iveta Benesova, Tsvetana Pironkova, Marina Erakovic, Pauline Parmentier, Alberta Brianti, Romina Oprandi, Anna Tatishvili, Eleni Daniilidou, Stephanie Foretz Gacon, Lesia Tsurenko and Olga Govortsova.