With Beale in mesmerising touch, the Rebels scored four tries to two in the first half to take a handy 26-15 lead into half-time.
The Force tightened up their defence in the second half, eventually taking the lead for the first time in the 73rd minute with a Ben Seymour penalty.
But the in-form Beale brought his kicking boots across the Nullarbor and calmly landed the match-winner from a tight angle with three minutes remaining after Melbourne had received a scrum penalty.
The Rebels may be out of finals contention, but their bonus-point win in this game enabled them to leapfrog the Waratahs into third spot in the Australian Conference table.
The Rebels picked up where they left off last week against the Crusaders, with second-rower Cadeyrn Neville charging onto a deft Nick Phipps pass to crash over for a converted try in the just the fourth minute of play.
Force full-back Dave Harvey was unsuccessful with his first penalty attempt but had no trouble with a simple shot in the 16th minute to leave the home side trailing 7-3.
Strong lead-up play from Beale and winger Mark Gerrard paved the way for the Rebels' second try in the 21st minute, with skipper Gareth Delve scoring in the left corner off a pin-point Julian Huxley pass.
Beale landed the sideline conversion to push Melbourne out to a 14-3 lead.
The Perth-based side grabbed a much-needed five-pointer a couple of minutes later when winger Napolioni Nalaga carried defenders over the line, but Harvey missed the easy conversion.
Melbourne struck back almost immediately when Gerrard snaffled the ball from the restart, leading to Neville securing his second try in the left corner a few phases later.
Beale's radar from wide out was again on target to give the Rebels a 21-8 lead after 27 minutes.
Force second-rower Ben McCalman fought his way over on the half-hour to reduce the deficit to six points, but the Rebels had the final say of the first half when former NRL player Cooper Vuna steamrolled Dave Harvey to score in the left corner after some slick passing from Beale and Huxley.
Force replacement Alfie Mafi did it all himself five minutes after the resumption to bring the hosts closer at 26-22 behind.
A blow-up in the scrum in the 58th minute resulted in Rebels prop Rodney Blake being placed on report and penalised, allowing Force half-back Brett Sheehan to land a long-range penalty and cut the arrears to one.
Beale and Seymour traded penalty goals for their respective sides to maintain the one-point margin in favour of the visitors, but a costly yellow card to Force forward Matt Hodgson in the 69th minute meant his side would be reduced to 14 men for virtually the remainder of the game.
The Force hit the lead for the first time in the match with seven minutes to go when the Rebels were caught offside, allowing Seymour to slot a simple penalty goal.
But the Rebels received a scrum penalty with four minutes remaining, giving Beale the chance to steal the game for his side.
He displayed great composure under pressure to navigate the ball through the sticks from a sharp angle and confirm back-to-back victories for the Rebels for the first time in 2012.