Client object model: orderby in camlquery doesn't work

I have a list on SharePoint 2010: (only showing the first item)

How can i get that list alphabeticly? I use a camlquery to try this but it doesn't work. I do get the list but it is in a random order. Am I doing something wrong?

List oList = clientContext.Web.Lists.GetByTitle(listTitle);
                CamlQuery camlQuery = new CamlQuery();
                camlQuery.ViewXml = @"<View><Query><OrderBy><FieldRef Name='DisplayName'/></OrderBy></Query></View>";

                ListItemCollection listItems = oList.GetItems(camlQuery);
                clientContext.Load(
                     listItems,
                     items => items.Include(
                         item => item.DisplayName,
                         item => item["WikiField"]));
                clientContext.ExecuteQuery();