the most obvious thing you've missed is that you specified
1 noob.com, and delete all other noob.com
yet did not specify which one you needed to keep. In some cases it may matter and in others you may not care whether the row was first one entered, last one entered or any other.
Sorry, way too complicated and it doesn't address the problem at the database level, the duplicate entries are still there.
One solution is to declare a unique key on the table which you can delete later.
ALTER IGNORE TABLE tablenamehere
ADD UNIQUE (onecolumn, anothercolumn, thirdifyouneeditcolumn)
that will add the unique key across one or several columns and discard any duplicates based on that unique key. you can then drop or change the unique key.