deleteItem

Method which deletes the table row passed as an argument or the row corresponding to the index passed as an argument.

deleteItem(gridItem) or deleteItem(index)
gridItem	HTML row object -
The row that will be deleted.
index	Integer	The row corresponding to the index will be deleted.

Example:

function DeleteFirstItem() {
    var masterTable = $find("<%= RadGrid1.ClientID %>").get_masterTableView();
    masterTable.deleteItem(masterTable.get_dataItems()[0].get_element());
}