You can't do without the two

Not quite true.

Some PhD programmes only specify that a Bachelors degree is required to enter. However, the applications procedure is usually a competitive one for any decent PhD and if you haven't got a Masters, you're indeed not all that likely to get an offer. Here's a couple of examples:

http://www.ed.ac.uk/studying/postgraduate/degrees?r=site/view&id=873&cw_xml=. - University of Edinburgh: "To study at postgraduate level you should have a first degree in an appropriate subject or relevant qualifications and experience."

http://www.findaphd.com/search/PhDDetails.aspx?CAID=277 - University of Bath: "We invite applications from Science and Engineering graduates who have, or expect to obtain, a first or upper second class degree and have a strong interest in Sustainable Technologies."

But doing a PhD with just a DELTA... Nope. He might be able to do a 'BSc' though... http://www.quickmeme.com/img/b1/b14697914dde77c4a2f26e3d3576652fd7be0dfc927b47059d23ee88eba6ac59.jpg