Western Force Head Coach Michael Foley says that they need to find more consistency in their performances after they were well beaten 41-7 at Canberra stadium by the Brumbies.
The result came after solid performances from the Force against the Crusaders and Hurricanes in the past fortnight.
The Force allowed the Brumbies to gallop out to a 29-0 half-time lead and, while the second term proved a more balanced contest but Foley said his side could not afford to provide opposition sides with that number of opportunities moving forward.
"Playing against one of the top sides, we knew we had to execute early and we didn't do that," he said.
"There were some unforced errors and the Brumbies were good enough with their line speed and defence - which we knew were going to be strong - to create some more for us."
"The Brumbies played very well but there were some times out there that we made errors that cost us."
The Western Force managed a late try through Matt Hodgson, when the Western Australian skipper powered over off the back of a rolling maul from an attacking lineout with six minutes remaining.
Fullback Jayden Hayward added the extras to finalise the 41-7 result.
Foley said putting together back-to-back performances is a key challenge in the development of his young side.
"Every game we're chasing that little bit of consistency in our performance," he said.
"We've got a lot of young guys that are hitting highs some weeks but not necessarily able to back that up; but over time you develop that consistency and certainly playing the derby games mean a lot to us and that's why we're so disappointed tonight."
The Western Force will return to Perth to face the Reds at nib Stadium next Saturday.