Hooker has experienced a nightmare build-up to the defence of his Olympic title but pulled off a morale-boosting leap of 5.72m to take third place at a meet in Poland.
It was well short of the height he cleared for victory in 2008 but would have been good enough for bronze in Beijing.
It is bound to lift Hooker's spirits after he failed to clear more than 5.42m since qualifying for the London Games in May.
"I saw the video of him jumping and I just sensed this sense of relief in his face," said Australian chef de mission Nick Green.
"Steve is a competitor and I think everyone will be inspired by the fact that he is starting to build his confidence."
In Germany, Australia's top two women triathletes made it a green and gold quinella in their last hit-out before the Games.
Erin Densham chased down her teammate Moffat over the last five kilometres to win by 12 seconds, lifting hopes that the Aussies will secure a second consecutive Olympic gold in London following Emma Snowsill's triumph in Beijing.
"I have been feeling a little flat all week but the further the race went, the better I started to feel," said Denham.
The news was nothing but bleak, however, for eventing competitor Shane Rose, who lost his spot in the Australian team after his horse Taurus showed signs of a shoulder injury.
A devastated Rose, part of the silver-medal-winning eventing team in Beijing, was close to tears as he decided to head home to Sydney before the Games even begin.
He will be replaced by reserve rider Megan Jones, also a 2008 silver medallist.
"I guess in our sport we are probably more used to disappointment than other sports, simply by the nature of our sport having another animal involved," Rose said.
The Hockeyroos, in the second of three Games warm-up matches, were handed a 4-0 drubbing by the top-ranked Netherlands.
Seventh-seeded Australia's medal prospects now don't look so bright as they failed to make an impact against the world number ones.
Basketball's Opals, chasing a gold medal in London after three consecutive silvers, had their perfect run to the Olympics spoiled by a 64-58 loss to France in their final warm-up match.