Rory Best admitted the British and Irish Lions let their standards drop in the 14-12 defeat to the Brumbies.
The tourists' lineout fell to pieces in Canberra as the they were deservedly beaten by a hungrier Brumbies side, and stand-in captain Best admitted the Lions could have no complaints with the result.
"We got physically beaten up front," said the Ireland hooker. "They put a lot of pressure on our set piece and we got a bit nervy.
"Credit to the Brumbies, they were hungrier than us right across the board."
The Lions had to cope with a mounting injury list ahead of the clash in Canberra Stadium but Best said the introduction of new players was no excuse for their below-par display.
"If you look across our team there was plenty of quality there," he said. "We just got beaten up at the breakdown tonight.
"We definitely got nervy at the lineout and certain units misfired. At this level, you're always going to be under pressure if you can't secure that ball.
"I think the forwards will stand up and take a lot of the heat, and deservedly so."
With the first Test against Australia just four days away, Best admitted the Lions have lost momentum.
"We let our standards drop tonight," he said. "It'll be up to 23 picked for this weekend to raise those again.
"We didn't want to lose the momentum that we've gained on this tour but that's what we've done. We now have to dust ourselves down and see where we go from there."