The veteran Irish centre, a member of the 2001 Lions who were overhauled 2-1 by the John Eales-captained Wallabies, had urged his colleagues to seize their chance and close out the series at Docklands Stadium.
His team mates obliged for all but the final minutes, before allowing centre Adam Ashley-Cooper to cross in the 77th minute and Christian Lealiifano to kick the Wallabies to a 16-15 lead they held through a nerve-jangling finish.
O'Driscoll, who did not play in the 1997 series win in South Africa, may have an uneasy feeling of deja vu after the tight loss at Docklands, having tasted disappointment at the same stadium 12 years ago.
The Lions also held a 1-0 lead in that series after winning the opener in Brisbane, but lost the series in the decider in Sydney after blowing a good chance to win the second test.
"Very disappointed, we weren't in control of the game but we were six points clear, that's a horrible margin as after a converted try you're behind," O'Driscoll told Sky Sports after putting in a typically fierce assault at the breakdown and making a number of big tackles.
"I had one loose kick that gave them a counter-attack option, but we weren't able to close it out."
It has been 12 years of Lions frustration for O'Driscoll, who was a member of losing sides in New Zealand in 2005 and South Africa four years later, and is only one of three Lions to have played in four series.
The Lions may also have lost captain Sam Warburton to a hamstring injury for next week's test in Sydney, another hit to the team's leadership stocks following the loss of former tour skipper Paul O'Connell.
The 34-year-old O'Driscoll's experience is likely to be called upon in a decider forecast to be even more taxing than the previous two blockbuster matches.
"It's not over, we've got a massive week to get ourselves ready for Sydney next Saturday," he said.
"The momentum is with them, but we won't let that faze us. We've beaten them once."
- Sports & Recreation
- Christian Lealiifano