White, who coached South Africa to their 2007 World Cup triumph, rated his side's 14-12 victory over the Lions at Canberra Stadium among the finest of his career, and said the result should erase any doubts among Robbie Deans's Wallabies ahead of Saturday's first Test in Brisbane.
"I would have said to you yesterday that it would have made no difference whether or not we won or lost," White told reporters.
"I think that the Lions know what's coming and they know what the expectation is.
"But looking now, I've no doubt that the boys sitting in the Wallabies camp would have looked at that result and looked at the performance of some of those young boys and said, 'Listen, it's do-able now'.
"I would say now, looking at that performance ... maybe a couple of days ago they would have thought it was a massive uphill battle."
The odds appeared stacked against the two-time Super Rugby champions Brumbies, who were shorn of their best players by the Wallabies' training camp and boasted only 28 test caps to the nearly 600 of their opponents.
But the home side played the damp conditions with aplomb, won the battle at the breakdown and defended stoutly to hang on for victory in a frenetic second half as the tourists came roaring home.
"We knew that we had to be combative at the breakdown, we had to present ourselves," White said.
"We couldn't afford that if the ball went around the corner to all those big players running over us, it would be a big ask for our young boys to be standing in the defensive line.
"We knew that one way we could really get some line speed was by getting into the breakdown and trying to make sure we could disrupt the ball."
Stony-faced Lions coach Warren Gatland, who put together a makeshift backline with three players flown in late from overseas, took heart from the Lions' improved second half but rued the loss of momentum after five successive wins on tour.
"We'll see on Saturday, won't we?" the New Zealander said when asked whether his team could still head into the first Test with confidence.
"We've been building nicely, there's been a lot of momentum, and maybe sometimes it's not the worst thing to take a bit of a knock and get a bit of a reality check, and we had that this evening.
"Maybe it's an indication for Australia that they may compete pretty hard at the breakdown but I thought the reaction after halftime was positive.
"We felt we were building nicely and everything was going along swimmingly.
"It's important that we learn from that experience and make sure that we're better than that for the next time we have our hit-outs."