Set Application As Root Of Default Web Site

I am using a single Windows Server 2008R2 and have a IIS 7 default web site setup with DNS pointing to a URL, we will use the example of www.abc.com (on default port of 80 and no host headers, very simple setup)

I have an application under the default web site,  we will use the example testapp

So my problem is that I can get to the application without issue using url: www.abc.com/testapp

BUT: The business wants to get to the app by going to www.abc.com without a redirect. Is it possible to configure IIS to do this without the DNS group changing anything?