Big swing against Labor in Rockingham puts WA premier 'on notice', gives Liberals hope
www.abc.net.au
Liberal Leader Libby Mettam says a 33 per cent swing against Labor on primary votes in the Rockingham by-election puts Roger Cook "on notice" in the lead up to the state election, as the result delivers gender parity in WA's halls of power.

I think this is likely the first time it has happened anywhere in Australia.