Tar and untar command help

Hi,
I 'm using below command to backup a directory and its sub-directories -
tar -C /u01/app/oracle/product/fmw -zcvf /home/oracle/test/fmw.tar.gz

but when extracting to specific directory i see u01 created
tar -zxvf /home/oracle/test/fmw.tar.gz -C /u01/app/oracle/product/fmw

cd /u01/app/oracle/product/fmw
ls -l
u01
fmw

Question is to backup /u01/app/oracle/product/fmw direcotry and its
file/subdirectories  and while restoring it should overwrite the fmw
directory.

Any help ?

Thanks,
hk