Casey Dellacqua made short work of Austrian qualifier Tamira Paszek, with a comfortable 6-2 6-2 triumph in 55 minutes.
Croatian-born Aussie, Ajla Tomljanovic followed Dellacqua's example in thumping Czech Klara Koukalova 6-3 6-4 in 71 minutes.
Defending champion Petra Kvitova made an emphatic start to her Wimbledon campaign but there were some high-profile casualties in the women's draw at the All England Club on Tuesday.
Kiki Bertens of the Netherlands was no match for Kvitova, who won 6-1 6-0 in 35 minutes as she began her quest for a third Wimbledon crown.
The Czech turned in an imperious serving display, dropping her first point on serve with a double fault in the final game of the match.
Eugenie Bouchard was beaten by Kvitova in the final last year but the out-of-form Canadian fell at the first hurdle this time around, beaten 7-6 (7-3) 6-4 by qualifier Duan Ying-ying.
The world number 12 has now lost eight of her last 10 matches and plans to spend time away from tennis to allow a stomach injury to heal.
Eugenie Bouchard - a beaten finalist in 2014 - falls at the first hurdle to world No.117 Duan Ying-Ying 7-6, 6-4 pic.twitter.com/iNqY4y7jOA
— Wimbledon (@Wimbledon) June 30, 2015
Fifth seed Caroline Wozniacki made a slow start against Duan's Chinese compatriot Zheng Saisai, falling 4-1 and two breaks behind in the opening set, before winning 12 of the next 13 games to prevail 7-5 6-0.
Simona Halep was on the receiving end of a comeback as she became the highest seed to exit in the first round.
Slovakia's Jana Cepelova ceded the opener 7-5 to the third seed but the world number 106 battled back to take the subsequent sets 6-4 6-3.
Angelique Kerber dealt out a devilish thrashing to fellow German Carina Witthoeft, who became the third player in the round to suffer a 6-0 6-0 loss.
Kerber won the Wimbledon warm-up event in Birmingham and the number 10 seed's passage to the next stage was never in doubt.
Caroline Garcia of France, the 32nd seed, came unstuck in a final-set shoot-out against British number one Heather Watson.
The duo were locked at one set apiece when play ended on Monday and Watson sent the home crowd into raptures, saving match points before taking the decider 8-6.
Fellow Brit and former Wimbledon girls' champion Laura Robson went down 6-4 6-4 against Russia's Evgeniya Rodina on her return to grand slam action.
Russian eighth seed Ekaterina Makarova cruised past Sachia Vickery 6-2 6-4, while Agnieszka Radwanska easily beat Lucie Hradecka 6-3 6-2.
Svetlana Kuznetsova was untroubled by Laura Siegemund in a 6-3 6-4 victory, Timea Bacsinszky overcame Julia Goerges 6-2 7-5 and Sabine Lisicki beat Jarmila Gajdosova 7-5 6-4.
Jelena Jankovic needed two hours and 40 minutes to edge Elena Vesnina 6-4 3-6 10-8, Garbine Muguruza was a convincing 6-4 6-1 winner against Varvara Lepchenko and Elina Svitolina got past Misaki Doi 3-6 6-3 6-2.
Anastasia Pavlyuchenkova was tested before beating Mona Barthel 6-7 (3-7) 7-6 (7-4) 6-2, while seeds Camila Giorgi and Alize Cornet got through in straight sets.
Also progressing were Magdalena Rybarikova, Kristyna Pliskova, Denisa Allertova, Christina McHale, Kurumi Nara, Monica Niculescu, Lara Arruabarrena, Silvia Soler-Espinosa, Olga Govortsova, Tatjana Maria and Mirjana Lucic-Baroni.