By Dean Southern SYDNEY (Reuters) - Ange Postecoglou enjoyed a winning start to his tenure as Australia head coach with Tim Cahill's second half header enough to see off Costa Rica 1-0 in a friendly between World Cup finalists on Tuesday. The New York Red Bulls substitute rose highest to meet Tommy Oar's 69th minute corner from the left to leave the 20,165 fans at Allianz Stadium happy after a promising first display by the hosts under the new manager. "Tonight was a good starting point," Postecoglou told reporters. That was because our pressure, our commitment and our discipline was fantastic." Postecoglou took the reins after German Holger Osieck was dismissed last month following the back-to-back 6-0 maulings by Brazil and France. More...