UPdate to 3.4.2 Database error

Hi folks, I was doing a normal wordpress update within wordpress on this site, to the current secure version, and the update failed and I can no longer log into the back end. I keep seeing this error:

Fatal error: Call to undefined method dbrc_wpdb::delete() in /home/ivanf/public_html/wp-includes/option.php on line 370

I need to get control back over the site.. Any advice on what I might do?