Page_Load and Async Calls - why doesn't the page load/render

On Page_Load() I want to call a web service Asyncronously using Begin/End Method or MethodAsync; however, no matter what I do the Page will not render, it waits for the Async methods to complete (Doesn't that just make them Sync operations??)
Is there a way to fire and forget a long running web service method Asyncrounously and render the page?  Some operations can take 15 minutes.  Users don't want to wait that long for the page to display.  If I have to use two pages, that is fine..at button_click event on page 1 that then calls the begin/End method or methodAsync and redirects to another?  I tried that without success...it just sits on the page 1.
I need to let users call methods and then allow them to go to other pages to do other work.  Any help with code examples (prefer VB.Net) would be GREATLY appreciated.  We really need to get over this hump badly.
Thanks,
Kevin
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