COLOMBO: Shane Watson's allround performance powered Australia to an easy seven-wicket victory over Ireland in their opening Group B match of the Twenty20 World Cup on Wednesday.

Opening the bowling, Watson claimed three wickets for 26 and returned to hammer a 30-ball 51 as Australia chased down the 124-run victory target with 29 balls to spare.

Watson removed Irish captain William Porterfield with the first ball of the match and later broke a dangerously-looking fifth wicket partnership between the O'Brien brothers, Niall (20) and Kevin.

Ireland, having elected to bat first, never really recovered since losing their captain to the first ball but managed to post 123 runs for seven wickets largely because of the 52-run fifth wicket stand between the O'Brien brothers.

Kevin O'Brien was the top scorer for Ireland with 35 runs off 29 balls with five boundaries before being dismissed off a Watson delivery.

DID YOU KNOW? By Shaan Agha

-Australia's Brad Hogg made his first class debut in 1993; it was the same year that Pat Cummins was born in.

- Australia found itself ranked below Ireland even when Bangladesh was the only Test qualified team that Ireland had beaten in all T20 internationals.

- Mathew Hayden was the highest run getter at the inaugural ICC World Twenty20 2007/08. He scored 265 runs in 6 innings.

- Alex Richard Cusack is up against his home team. He was born in Brisbane and moved to Ireland as recently as 2005. Two years later he was able to make his international debut for Ireland in 2007.

- Ed Joyce along with his brother has played international cricket for Ireland while their two sisters have played for the women’s national team. They have another brother who has played first class cricket. Ed has also represented the English national team.

- 28 year old fast bowler, Boyd Rankin has announced his retirement from Ireland which will come into effect at the end of this year so he can pursue his hopes to play Test Cricket for England.

Australia: George Bailey (capt), David Warner, Shane Watson, Matthew Wade, Michael Hussey, Cameron White, Daniel Christian, Glenn Maxwell, Brad Hogg, Mitchell Starc, Pat Cummins.

Ireland: William Porterfield (capt), Alex Cusack, George Dockrell, Trent Johnston, Nigel Jones, Ed Joyce, Kevin O'Brien, Niall O'Brien, Boyd Rankin, Paul Stirling, Gary Wilson.

Umpires: Aleem Dar (PAK) and Kumar Dharmasena (SRI) TV umpire: Asad Rauf (PAK) Match referee: Ranjan Madugalle (SRI)