Problem with browser saving credentials

I have email and 2 password fields in the registration form, but after the auto login the browser suggests to save email instead of username with the password, I guess because email field is placed next to password field.
It may be primarily a browser problem, but I experienced with our users that it is a constant source of misusage and leads to having people reset their password without need or not saving it.

How can I place the common username field in registration directly above the password fields?