Big Welsh wingers George North and Alex Cuthbert scored tries and fullback Leigh Halfpenny landed both conversions and kicked three penalties.
Israel Folau scored two first-half tries on debut for Australia to erase any questions over his ability to handle international rugby. But James O'Connor didn't really make the transition to chief organizer at flyhalf for the Wallabies, and missed three shots at goal. The recalled Beale pushed a penalty attempt wide in the 75th, missing his first chance to put the Wallabies in front, and slipped as he attempted what could have been the winning goal in the last minute.
"That was entertaining, that's for sure — way too close for comfort," Lions captain Sam Warburton said. "We can expect a lot more of this in the last two matches. Both sides were pretty even today, it went down to the last 10 seconds."
The Lions maintained their unbeaten run in eight tests in Brisbane, where they also won the opening test in 2001 before the Wallabies rebounded to win the second and third tests and claim the series. But the Australians have serious backline injury concerns and will have to regroup quickly before the second test next Saturday in Melbourne, with centre Christian Leali'ifano lasting one tackle before he was carried from the field, and fullback Berrick Barnes and replacement Pat McCabe also leaving the field with head injuries on either side of halftime. That forced Wallabies coach Robbie Deans to shift openside flanker Michael Hooper into the midfield and allowed the Lions room for their second try.
On Sunday, the Wallabies' news got worse when captain James Horwill was cited for stamping or trampling on lock Alun-Wyn Jones in the third minute. Horwill will appear at a judicial hearing later Sunday in Melbourne.
Horwill said the narrow defeat was a bitter disappointment.
"We were right in it, a couple of little errors," were costly, he said. "In the end we have to be a lot more clinical and take advantage of our opportunities."
The highlight for the Australians was Folau's two tries on the right wing.
"He is a freak of a talent. He has the X factor," Horwill said. "When he gets his hands on the ball, things happen."
O'Connor never really settled into the pivotal No. 10 role, starting nervously when he missed penalty attempts in the fifth and seventh minutes.
The Wallabies absorbed plenty of pressure from the Lions forwards in phase after phase of pick-and-drive and rolling mauls before getting a penalty in their own quarter in the 13th minute. The Australians took a quick tap and scrumhalf Will Genia dummied and swerved in and out to beat his opposite Mike Phillips before sprinting down the right line, looking for somebody to run inside before dropping the ball onto his toe for Folau to pick and cross untouched for a try on debut.
Halfpenny made no mistake with his first goal in the 25th minute and the Lions hit the front in the next minute with North's counter-attacking try after receiving an aimless deep kick from Barnes.
The 21-year-old North beat two tacklers and swerved around Barnes before beating the cover defence to the corner. Halfpenny converted and then kicked another penalty goal in the 32nd minute after North was bundled in to touch millimeters from crossing for another try in the left corner.
Folau scored his second try in the 35th minute, a solo effort from 25 metres out when he stepped inside Jonathan Sexton and beat Halfpenny on his way to the line, but O'Connor missed the conversion and the Lions led 13-12 at the break.
Beale went on just before half time as a replacement for Barnes, who sustained another head knock. McCabe, who went on in the first minute to replace new cap Leali'ifano, left the field injured in the 47th minute after a collision with Cuthbert, who made the most of the extra room in midfield to slice the Wallabies defence in the 49th minute and extend the Lions lead to 20-12.
The kickers dominated the last half hour in a physically grueling match, with O'Connor and Beale landing goals in the 52nd and 62nd minutes, Halfpenny replying with one in the 66th and Beale scoring again in the 68th. But it was his misses in the last five that will haunt Beale, recalled by Deans despite a series of disciplinary issues this season.
After his miss in the 75th, the Australian pack earned a rare scrum penalty 45 metres out and directly in front with only seconds remaining. Beale slipped as he approached the tee and slumped to the ground as he watched the kick fade away as the siren sounded, sparking joyous celebrations from the Lions.
"In all, it wasn't the prettiest performances but it was the victory we deserved," said Lions coach Warren Gatland, who is one victory away from ending a series drought for the Lions dating to 1997. "Now we've got the opportunity to wrap it up next week."