To expand slightly: Right now, there's now way to fly from GVA to SYD (or anywhere in Australia) without touching down in Asia (at SIN,BKK,HKG or NRT). Just "touching down" even if it's on a single flight coupon/flight number still counts Asia as a continent.

In a few years when we have aircraft capable of LHR-SYD nonstop things may be different, but right now you can't get to Australia without a four continent ticket.

Steve