The ACT Brumbies will persist with their helter skelter breakdown mentality despite conceding almost double the amount of penalties the NSW Waratahs did and having two players sent to the sin bin on Saturday night.

But coach Stephen Larkham says the Brumbies have to make smarter decisions and skipper Ben Mowen is adamant the team has to improve its discipline.

The Brumbies were a force at the breakdown against the Waratahs, but conceded plenty of penalties.

The Brumbies held on to beat the Waratahs 28-23 on Saturday night.

But they almost paid a heavy price for constantly challenging at the ruck in the last 20 minutes, losing Matt Toomua and Ruan Smith to the sin bin as referee Jaco Peyper got fed up with repeated team infringements.