How can I pass a html table row into DataTable.net fnAddData

I am using the DataTable.net plugin and I am wondering how can I add dynamically a row to a existing table?

http://datatables.net/examples/api/add_row.html

I am looking at this example and they have it like this

/* Global variable for the DataTables object */
var oTable;

/* Global var for counter */
var giCount = 2;

$(document).ready(function() {
    oTable = $('#example').dataTable();
} );

function fnClickAddRow() {
    oTable.fnAddData( [
        giCount+".1",
        giCount+".2",
        giCount+".3",
        giCount+".4" ] );

    giCount++;
}

but I am wondering what happens if I want I have a table row already rendered?

Say this is my table.

<table border="1">
<tr>
<td>row 1, cell 1</td>
<td>row 1, cell 2</td>
</tr>
<tr>
<td>row 2, cell 1</td>
<td>row 2, cell 2</td>
</tr>
</table> 

Now I have this

var newRow = '<tr><td>row 3, cell 1</td><td>row 3, cell 2</td></tr>';

How can I add it through addRow?

I tried oTable.fnAddData(newRow); but that seems not to work.

So I am not sure how to do this.