UPDATE:The Rebels will head to Africa with a 3-0 record after a comeback 29-26 win over the Brumbies but both Aussie sides could be missing Wallabies when round five rolls around.
Down by 16 points at half-time on Friday night the Rebels scored four tries to one in the second half to take the lead for the first time in the 70th minute and hang on for the win.
Coach Dave Wessels had plenty of praise for his side's resilience to fight back after having two men in the bin and trailing by so much by the time the break came.
"That's a huge growth for our team because I think in the past those sort of things would have totally thrown us but we just got connected pretty early and the guys talked about it and we solved those problems as they came up which was good."
His Brumbies counterpart, Dan McKellar, was "shattered" after his team let their commanding lead slip in the second half.
"Shattered...it was incredibly disappointing," he said.
"The sun will come up tomorrow and you've just got to keep pushing on because that's part of it.
"You've got to be able to understand why we feel this way and use it as motivation to avoid it in 7 or 8 days."
The Brumbeis will be sweating on possible injuries to Test duo Allan Alaalatoa and David Pocock as well.
Alaalatoa came off with a shoulder injury midway through the second half while flanker Pocock also pulled up with a tightcalf, putting him in under a cloud ahead of next Friday's clash with the Waratahs.
"David was quite tight in his calf so that was an injury replacement," McKellar said.
"How he is leading into next week, we'll see. Has he just cramped up? he hasn't played a lot of footy either, so we'll have that assessed by our medical staff and see where we get to."
Wessels will also have some selection dilemmas with his Wallabies contingent not linking up with the rest of the squad in Africa until next Tuesday due to a Wallabies camp being held this weekend.
The bulk of the team will fly to Johannesburg on Saturday and Wessels said it would give him food for thought when it came to selections for the Lions game on Sunday week (AEDT).
"All of the Wallabies have got a camp until Tuesday and they'll land in South Africa late Tuesday," he said.
"It might do (affect selections)."
The Canberra outfit was dominant in the first half as the Rebels unravelled themselves with poor discipline but Melbourne steadied themselves and, led by a seemingly possessed Will Genia, found the space and spark they couldn’t in the opening 40 to claw their way back.
It was a slice of Genia genius off a scrum that put the Rebels within striking distance in the 64th minute, taking a quick tap from a penalty advantage and seizing the opportunity.
The scrumhalf also started the chain that ended in a Quade Cooper spiral to Jack Maddocks five minutes later, lighting up the AAMI Park crowd.
Both sides predicted an early grind and that’s exactly what was delivered early, with set piece opportunities opening up at either end of the field.
Tom Banks had the first half-chance more than 10 minutes into the game and though he couldn’t go the distance, it sparked a period of Brumbies dominance.
The Brumbies tried to flex their Wallaby front row muscle in their attacking zone, opting for repeated five metre scrums against Rebels debutant Matt Gibbon.
They finally got their reward when scrumhalf Joe Powell spotted winger Henry Speight on the right edge and sent a long-range pass to the speedster, who dove over just inside touch.
Discipline proved the downfall in the Rebels’ efforts as well, as they conceded nine penalties to just three by the break and the yellow cards came with that as well.
When lock Adam Coleman was sent to the bin in the final 10 minutes of the second half, things looked grim and Brumbies hooker Folau Faingaa went over
They were left even further depleted just shy of the half, conceding a penalty try and losing Gibbon to the bin.
Marika Koroibete gave the Rebels the perfect start to the second half, barrelling over just a minute into the back end.
When Maddocks went over less than 10 minutes later, the Brumbies were the side who had begun to unwind as the hosts began breathing down their necks.
Genia was openly frustrated by some of his team’s errors and it seemed the Test halfback took it upon himself to provide the spark as the second half ticked on.
Rob Valetini looked to have notched a pressure reliever for the Brumbies but his effort at the post was disallowed.
Just two minutes later, though, he had his score, after Pete Samu burst off the side of the scrum, with Joe Powell linking up with Valetini to put the blindside over.
The Rebels were certainly not lying down, though, and Genia went one better than his Melbourne counterparts to score before Maddocks’ second stole the lead and ultimately the win.
Tries: Maddocks 2, Koroibete, Genia
Yellow cards: Coleman (30’), Gibbon (39’)
Tries: Speight, Faingaa, Penalty, Valetini