Tim David and Mitchell Marsh starred in Australia's nail-biting six-wicket victory over New Zealand in the first T20I in Wellington on Wednesday. Chasing a target of 216, Australia needed 12 runs off the final three balls. David smashed New Zealand pacer Tim Southee for a six to fine leg. On the next delivery, the right-handed batter managed to steal a couple. Australia needed 4 runs to win off the final ball and David took them home by whipping…