res.render not rendering view, returns html text

Calling into express/node thus:

jQuery.ajax({
            url : url,
            type: "GET",
            data: {names : names},
            success: function(data) {
                console.log("ajax post success");
            },
            error: function(jqXHR) {
                console.log(jqXHR.responseText + ' :: ' + jqXHR.statusText);
            }
        });

In express router.js:

app.get('/metrics/:title/:node/:metric', function(req,res) {
    console.log("received request " );
console.log(req.query.names);
    res.render('nltuning', {
        locals: {
            tdata : req.params.title,
            gdata : req.params.node,
            mdata : req.params.metric,
            ndata : req.query.names
        }
    } );
});

All console msgs are printing correctly, ajax success is printing. ajax shows html text in response.

and the view is not rendered. Same for POST, GET - why is it ?

if i type in the same url in a browser window, the view is rendered. any pointers appreciated.