The Brumbies were outplayed and outmuscled against the NSW Waratahs at ANZ Stadium.

But in the sign of a championship team, Jake White’s men held on for a 19-15 victory tonight.

It means they are five points clear at the top of the Australian conference with just one round remaining in the regular season.

The only stumbling block for the Brumbies entering the finals will be if the Queensland Reds win and they lose.

Positions on the ladder are decided by win tallies if teams are tied on competition points. Both the Brumbies and Reds have 10 wins going into the last round.

The Brumbies can afford to lose if they secure a bonus point for losing by less than seven points if the Reds beat the Waratahs.

The Reds need a bonus-point win over the Waratahs and the Brumbies to stumble to leapfrog and steal the guaranteed finals spot.

The Brumbies play the Auckland Blues at home next Saturday afternoon.

Tonight was a massive moment for the new era Brumbies.

It was their first win in Sydney since 2002 and just the second in the club's history.

Everyone had written them off at the start of the year, but they have defied the odds and everyone's expectations to be a title contender.

Their win against the Waratahs was ugly, but it got the job done and secured five consecutive wins on the road for the Brumbies for the first time in their history.

White would have felt relief more than anything after the final result.

But now the finals shackles are off, it could free them up to play expansive rugby next weekend.

Captain Ben Mowen praised his team's defence after withstanding a Waratahs onslaught the entire match.

"There was always going to be nerves at this time of the year. But I'd rather have them, that means the guys are focused and ready for the job. It wasn't the win we wanted, but it's a win," Mowen said.

"It's a massive moment for the guys, we keep breaking these hoodoos and keep moving forward.

"We couldn't get into our rhythm early on."

The Brumbies were forced to hang on the opening exchanges with the Waratahs holding on to the ball for the first eight minutes.

But the well-drilled defence held on and chipped away in attack to take the lead with a Zack Holmes penalty goal in the 12th minute.

The Waratahs signalled their intent when they twice turned down a penalty shot from in front of the posts and instead opted for attacking scrums.

It paid off when after more than five minutes of attack, Waratahs hooker Tatafu Polota-Nau crashed over from close range to cut the Brumbies' lead to just one point

Despite having just 38 per cent of possession in the first half, the Brumbies held on to a 9-5 lead at the break.

The Waratahs were prepared to play a more attacking style and run the ball from almost anywhere while the Brumbies tried to stick to their game plan and play territory.

They weathered the storm at the start of the second half as well as the Waratahs launched another raid on the Brumbies' line.

Somehow the defence held on.

Whenever it seemed as if the Waratahs would score, the Brumbies would turn up to protect their line.

Berrick Barnes cut the lead back to one point with a penalty goal early in the second half and the Brumbies couldn't get into the contest.

Eventually the weight of possession took its toll when Barnes bounced off the post to score the Waratahs' second try, giving them the lead for the first time in the match.

When the Brumbies finally got into their attacking 22m, flyhalf Holmes floated a ball wide to Henry Speight who broke the try drought.

It breathed life back into the Brumbies who had been wobbly all night. They lacked their usual punch and precision as the Waratahs took control and were intent on spoiling the party.

The Waratahs lacked the composure to steal the result back in the dying minutes as the Brumbies breathed a sigh of relief.

ACT BRUMBIES 19 (Henry Speight try; Zack Holmes 2, Jesse Mogg 2 penalties; Zack Holmes conversion) bt NSW WARATAHS 15 (Tatafu Polota-Nau, Berrick Barnes tries; Berrick Barnes penalty, conversion) at ANZ Stadium last night. Referee: Keith Brown. Crowd: 22, 844.