In second place, new entry Step Up 3D provides stiff competition for the Leonardo DiCaprio-led thriller, while last week's runner-up Killers is in third place.
Rounding out the top five are Knight And Day and Pixar's Toy Story 3, which has now crossed the $40 million mark Down Under less than two months after opening.
The chart also sees new releases The Special Relationship, the Blair/Clinton movie starring Michael Sheen and Dennis Quaid, and Roman Polanski's The Ghost Writer debuting at numbers eight and nine respectively.
The box office top ten in full (figures in Australian dollars):
1. (1) Inception - $4,163,040
2. (-) Step Up 3D - $3,176,113
3. (2) Killers - $1,129,625
4. (3) Knight And Day - $617,669
5. (4) Toy Story 3 - $547,317
6. (5) The Twilight Saga: Eclipse - $438,286
7. (6) The Karate Kid - $328,958
8. (-) The Special Relationship - $169,214
9. (-) The Ghost Writer - $165,808
10. (8) Grown Ups - $137,746