I'm not quite sure what you're looking for but it sounds like you need
an async trigger.
<updatePanel id="pnlUp" runat="server">
    <contenttemplate>
         <!--Stuff -->
    </contenttemplate>
    <triggers>
         <asp:asyncronouspostback controlid="btnPost"
eventname="click" />
    </triggers>
</updatepanel>

Oleg ,
You can add the following code to your click event handler of the
link
button

UpdatePanel upd = new UpdatePanel();

           upd.ID = "UpdatePanel1";
           upd.UpdateMode = UpdatePanelUpdateMode.Conditional;
           upd.Update();