Wales captain Sam Warburton was left "speechless" after his side saw victory in the second Test against Australia snatched from their grasp.
The final hooter had already blown when Mike Harris, who had replaced Berrick Barnes in the 73rd minute, kicked the winning goal for the Wallabies to seal a 25-23 win in Melbourne after Wales had been guilty of pulling down a driving lineout.
"It's so demoralising to come so close and I'm speechless. I'm just gutted," admitted Warburton.
"It's difficult to stop a team when it gets momentum at a lineout drive. Now we have to pick ourselves up for next week. That won't be difficult, though, because we're desperate to get a southern hemisphere scalp.
"We have shown good character all season and this result will motivate us even more."
Wales caretaker coach Rob Howley blamed a lack of composure for his side's last-gasp defeat.
"We spoke in the changing rooms about lacking composure. We gave Australia the opportunities, not just in the last 10 minutes, but at other points in the game when our emotional intelligence and composure wasn't good enough," said Howley.
"We are hugely disappointed having outscored Australia two tries to one. Our defensive effort throughout the game without the ball was outstanding and we negated a lot of their strengths.
"We stopped Will Genia doing what he did last weekend and we negated a lot of their power runners. But those are the fine margins that make the difference in international rugby.
"We gave them those opportunities with two moments of indiscipline and, like any top side in world rugby, they took them."