Can I get rsync to delete missing files first?

[Allistar]

I am backing up a remove partition which is 38Gb onto a local partition
which is 40Gb. Rsync is complaining that I have run out of disk space on
the local partition, and I can tell that this would not happen if local
files that are missing in the remote system were deleted BEFORE copying
down new files.

I note there is a --delete-after option, but is there a --delete-before
option? If not, can I simulate this somehow?

This is rsync version 2.6.2 protocol version 28

Thanks,
Allistar.