A stunning set-piece winner from Terry Kennedy helped Ireland to a major shock over Australia in their Cape Town Sevens opener.
Ireland took advantage of their man advantage from a line-out on the halfway line, with Kennedy's dummy pass giving him the gap to race to the corner from his own half for a 26-21 comeback win.
It was a dramatic turnaround from their 45-21 loss to the same opponents eight days earlier in Dubai, as Aaron O'Sullivan, John O'Donnell, and captain Billy Dardis also crossed for Anthony Eddy's side.
Ireland finished 12th of 16 teams in Dubai, with Australia fifth, but Ireland have now put themselves in a good position to qualify for the quarter-finals as they head into games against Samoa and Kenya on Saturday.
"We're thrilled but we can't get ahead of ourselves," said Dardis. "We had a good chat inside after that and the lads are well hyped up. We have to go at it again, repeat the performances, and go better. But a great start to the weekend.
"We were pretty disappointed after last weekend. It was a bit embarrassing, to be honest with you. We didn't really put our best foot forward. To go out and put a performance like that against a side that pumped us last week is really encouraging."
Ireland Women's side suffered a difficult start in Cape Town as they were whitewashed 38-0 by the USA. They face Australia and England on Saturday.