UpdatePanel in EditItemTemplate of Gridview causing full page refresh

I tried to search for solutions, but couldn't find any. Everywhere they are talking about Gridview within UpdatePanel. In my case I have an UpdatePanel within the EditItemTemplate of a Gridview and a DropDownList in that EditItemTemplate is causing postback on SelectChange event. I just want that cell or at most that row of the gridview to be partially rendered, but the whole page flashes.

I have used an update panel elsewhere on that page, but outside the gridview, and it is working fine.

Is UpdatePanel not supported within Gridview templates?

Thanks!

You need to specify AsyncPostBackTrigger inside the <Triggers> element for the UpdatePanel . I tried same and it was working.

<asp:UpdatePanel ID="upSetSession" runat="server">
            <ContentTemplate>
                <asp:DropDownList ID="ddlMyList" runat="server" 
                    onselectedindexchanged="ddlMyList_SelectedIndexChanged"
                    AutoPostBack="true">
                    <asp:ListItem>One</asp:ListItem>
                    <asp:ListItem>Two</asp:ListItem>
                    <asp:ListItem>Three</asp:ListItem>
                </asp:DropDownList>
            </ContentTemplate>
            <Triggers>
                <asp:AsyncPostBackTrigger ControlID="ddlMyList" 
                    EventName="SelectedIndexChanged" />
            </Triggers>
        </asp:UpdatePanel>