The Rebels, who are facing being axed from the Super Rugby competition, defended like their lives were on the line and hit the front with two minutes left to win 19-17 at AAMI Park.

It broke the Brumbies' run of 10 consecutive Australian derby wins and ended the Rebels' horror start to the year.

But it was made harder to swallow after the Brumbies scored three tries to one and the Rebels had three players sent to the sin bin at different stages.

Wallabies great Tim Horan said the Brumbies didn't "fire any shots" in the second half and winger Henry Speight, who scored two tries, conceded the ACT side may have been a "little bit complacent.

"The Rebels had a few things on the night and they showed really good resolve to come back, they never stumbled and it's a good learning for us," Speight said.

"A little bit complacent, but in saying that the Rebels were really good at the breakdown and we couldn't really get our groove going. It was a bit stop-start and we didn't adapt quite as well as the Rebels."

Rebels inside centre Reece Hodge's boot was the difference, kicking four penalties and a conversion to secure a vital win.

The Rebels fired a message to the ARU, showing plenty of guts when Colby Faingaa and Lopeti Timani were sent to the sin bin at the same time and then prop Fereti Saaga followed in the second half.

Brumbies coach Stephen Larkham conceded he felt Timani could have been punished with a red card given he attempted to knee Rory Arnold in the head.

But he said there were "no excuses" for poor execution and failing to put the vulnerable Rebels to the sword.

"It was a knee to the head, so I guess it's a red card, isn't it?" Larkham said.

"You don't want a guy to get sent off to win a game, you want to play well ... it was a pretty ordinary game to watch. Lots of mistakes, lots of penalties and it lacked momentum for both sides."

The Brumbies gave away 12 penalties and the Rebels conceded 10 in a stop-start contest that didn't live up to great heights.

The ARU is weighing up whether to cut the Rebels or the Western Force from the competition, leaving players, coaches and staff on tenterhooks in Melbourne.

Beating the top of the conference Brumbies just gives the ARU another week of headaches as both the Rebels and Force passionately defend their existence.

"We're really happy, you can see how the boys are celebrating," said Rebels skipper Nic Stirzaker.

"It's probably a reflection of where we've been. It's been a pretty dark place, not just on the field by off the field as well.

"So we're really pleased with that effort, the boys showed a lot of heart. It was a tight affair, these derbies always are. It took everything we had."

The Rebels' scrum, which had been dominated most of the match, won a penalty with time running out and Hodge stepped up to steal the lead.

In contrast, Brumbies kicker Wharenui Hawera nailed just one of four attempts. The only saving grace for the Brumbies is they walked away with a losing bonus point.

"We had a bit of momentum but we didn't capitalise. We couldn't make it happen, we're going to have to look at that and make amends next week," said Brumbies skipper Sam Carter.

"They put the heat on us for 80 minutes, they scrapped, and scrapped and scrapped to get it in the end. We need to be better in games like that."

The Rebels skipped out to a 10-0 lead early when winger Sefa Naivalu broke four schoolboy tackles to score the first try.

But all of their momentum was destroyed when Faingaa was sent to the sin bin for a lifting tackle and Lopeti followed him because he kneed Arnold in the head.

It changed the game, with the Rebels forced to play with just 13 men for 10 minutes and the Brumbies went straight on the attack.

"We fought and scrapped, the Brumbies were a little bit off and we needed that. But we still found a way ... we showed that grit," said Rebels coach Tony McGahan.

Speight scored his first when Faingaa and Timani were off the field, and then got across the line for his second just after half-time when Saaga was in the sin bin.

The Brumbies' scrum set up a try for Jarrad Butler late in the first half to put the visitors in front, but the Rebels refused to lie down.

They were desperate in defence, stifling the Brumbies and Hodge stepped up to the plate late to seal a breakthrough win.

AT A GLANCE

MELBOURNE REBELS 19 (Sefa Naiavalu try; Reece Hodge 4 penalties, conversion) bt ACT BRUMBIES 17 (Henry Speight 2, Jarrad Butler tries; Wharenui Hawera conversion) at AAMI Park. Referee: Glen Jackson.