2 workarounds
Add "MaintainScrollPositionOnPostback" property to your ASP.Net header as in...
<![CDATA[<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" MaintainScrollPositionOnPostback="true" %>]]>
Or, you can always add an ID to your gridviewrow somewhere (it could be the tr)
<table><tbody><tr id="OverHere"> .... </tr></tbody></table>
And transfer user to the address on post as in
http://theAddress/thepage.htm#OverHere