IRELAND CAPTAIN William Porterfield admitted his side fluffed their opening lines badly in Wednesday's Group B clash against Australia at the World Twenty20 as a poor batting display saw Australia complete an altogether too easy seven-wicket victory at the Premadasa Stadium in Colombo.

Ireland may have come into the tournament on a four-game winning streak since they arrived on the island two weeks' ago, but their hopes were dashed pretty quickly by an Australian side in which all-rounder Shane Watson was outstanding with ball and bat.

Watson had talked about the respect that the Australian camp had for Ireland in the build-up to yesterday's encounter and certainly they never let up once they made the early breakthrough.

Porterfield had won the toss and put his side in to bat on a wicket that looked like a batsman's dream. It quickly turned to a nightmare for the Irish skipper as he attempted to hook Watson's first delivery down the throat of Mitchell Starc at long leg.

It was a poor shot from Porterfield, who was also bowled first ball by Brett Lee in the rain-affected one-day clash between the sides in Belfast during the summer, and Watson was to return the favour to Starc when he made good ground at third man to hold on to a catch to dismiss the dangerous Paul Stirling for seven to leave Ireland on 15 for two.

Ed Joyce looked like he was relishing the challenge against a side he has scored a century against, albeit in an England shirt, but after a couple of beautiful boundaries he also went tamely, when he lobbed off-spinner Glenn Maxwell straight to David Warner at mid-off.

When Gary Wilson then failed to read Brad Hogg's left-arm chinamans, Ireland were in the mire on 33 for four, with 44 deliveries already bowled.

Kevin O'Brien knows all about performing on the biggest of stages, and along with his older brother Niall, he helped Ireland at least post a target. The pair put on 52 runs in 43 balls before Watson returned to get rid of them both; bowling Niall for 20 with an inswinger, before a slower ball saw Kevin guide an uppercut to wicketkeeper Matthew Wade after making 35 from 29 balls.

An unbeaten eighth-wicket stand of 22 from Alex Cusack and Nigel Jones, who hit the only six of the Irish innings, saw Ireland finish in 123 for seven, at least 40 runs short of a competitive total.

Early wickets were required against a top-heavy Australian batting line-up, but Watson and Warner mixed the sensible with the sensational as they took the game away from Ireland with a partnership of 60 for the first wicket off 43 balls.

George Dockrell pocketed the wicket of Warner for 26, but Watson looked set to bring his side home, only for an outstanding direct hit run out from Trent Johnston after he had made 51 off 30 balls.

Kevin O'Brien also claimed the scalp of Mike Hussey for 10 but Cameron White and Australian skipper George Bailey eased them home with 29 balls to spare.

Porterfield admitted the batting performance from the top order, including himself, was not up to standard.

"When you are four down for 30 odd in the powerplays, you are putting yourselves on the back foot. We have played enough cricket to know that's not where we are at. We should be better now, we should be giving ourselves a chance," was his harsh appraisal.

"To win the toss and bat first and to bat like that, that was the most disappointing thing for us. We let ourselves down."

Ireland will now hope that Australia can continue their winning start against the West Indies on Saturday and set up a winner takes all battle with them on Monday at the same ground.

Even if the West Indies beat Australia, Ireland could still sneak through on run rate if they defeated the Windies, although they would need to win by a considerable margin. On yesterday's evidence that looks a long shot.