Terry Kennedy ran in a last-gasp try as Ireland's men began the HSBC Cape Town Sevens with a 26-21 win over Australia.
Aaron O'Sullivan, John O'Donnell and captain Billy Dardis also crossed for Anthony Eddy's side at the Cape Town Stadium.
The team are back out tomorrow against Samoa (9.19am Irish time) and Kenya (2.47pm), with a good chance of progressing to the quarter-finals.
It was a tougher day for the women's team, who were beaten 38-0 by the United States in their Pool C opener.
Ireland struggled to retain possession and Stan McDowell's side allowed USA mount sustained pressure on their line and the Americans crossed for four first-half tries to lead 28-0 at the break.
Alev Kelter (2), Eti Haungatau and Lauren Doyle scored before the interval and while Ireland saw more of the ball in the second period, and very nearly crossed at the other end after an Amee-Leigh Murphy Crowe midfield break, USA held them out and then finished with a flourish to tack on two further scores.
It was a disappointing start to the campaign for Ireland, who must now pick themselves back up ahead of Saturday's clash against Australia (6.45am Irish time), before a final pool outing against England.
That's what you call clutch. Terry Kennedy hits the turbos and scores a final play winner for @IrishRugby against Australia at the #CapeTown7s#ImpactMoment #DHLRugby pic.twitter.com/1ywIDzJWVb
— World Rugby Sevens (@WorldRugby7s) December 13, 2019
