Khawaja, Hughes show Test form Usman Khawaja hits a four over midwicket as wicketkeeper Alex Barrow of Somerset looks on. Australia has made a winning start to the Darren Lehmann era. Phillip Hughes and Usman Khawaja contributed confident half-centuries against Somerset in aid of their quest to firm up Ashes spots, but Ed Cowan condemned himself to an anxious wait. All three left-handers played a part in Australia's untroubled runchase on Saturday, but none kicked on to a hundred. Cowan, in particular, would have been annoyed at letting slip a chance to cement the other opening spot, with Shane Watson already locked in at the top of the order. He looked in good touch until his dismissal but was caught behind for 46 off the bowling of seamer Gemaal Hussain for the second time in the match, this time swiping at a wide ball in pursuit of a half-century. With Chris Rogers waiting in the wings, and without a first-class hundred since his breakthrough Test ton against South Africa in Brisbane in November, Cowan's long battle to end the uncertainty swirling around his position continues. It remains to be seen whether he will have another chance, against Worcestershire next week, to do so. Hughes, who has been shifted away from the new ball in this game, did the most to enhance his prospects of playing in the first Test at Trent Bridge, adding 50 to his unbeaten 76 in the first innings. He twice hit left-arm spinner George Dockrell for six, once over mid-wicket and then over mid-off, before he was bowled attempting to slog-sweep the Irishman. Khawaja was caught at slip trying to defend for 73, having looked much more in command of the bowling than in the first innings. Australia began the final day of the tour match at Taunton hunting a further 224 runs to win, following an aggressive declaration on the third day of the match. At every opportunity since the sacking of coach Mickey Arthur, players have spoken of the importance of setting up a winning culture, which had turned toxic during the previous tour of India. A six-wicket win over Somerset, sealed when Brad Haddin (52 from 40 balls) creamed a six over mid-wicket, was a step in the right direction. Cowan looked in good touch until he was dismissed, and would have been disappointed to miss a chance to nail a spot, with Chris Rogers in the wings and set to play in the next match against Worcestershire. The 31-year-old has not scored a first-class century since his maiden Test ton against South Africa at the 'Gabba in November. The Australians were 1-153 at lunch. Among the bowlers, if James Pattinson is Ashes-ready, the same cannot be said just yet for his fast-bowling partner Peter Siddle. The older paceman has lacked his usual grunt as Pattinson and Mitchell Starc staked strong claims for Test spots. Meanwhile, the performance of Hughes at No.