The pair, who picked up gold at the Commonwealth Games last summer, posted a total of 293.40 in a highly competitive event that saw Canada's Jennifer Abel and Pamela Ware plummet from the silver position to fifth with a botched final dive.
Once again China claimed gold in the event as Shi Tingmao and Wu Minxia posted a title-retaining total of 328.50 to earn the host country its third gold from three events on the first day of the competition.
Results in full:
1. Shi Tingmao, Wu Minxia (CHN) - 328.50
2. Maddison Keeney, Annabelle Smith (AUS) - 299.55
3. Alicia Blagg, Rebecca Gallantree (GBR) - 293.40
4. Paola Espinosa, Dolores Hernandez (MEX) - 289.80
5. Jennifer Abel, Pamela Ware (CAN) - 287.82
6. Anastasiia Nedobiga, Viktoriya Kesar (UKR) - 280.02