Not only that, it was the first time the Brumbies had beaten the Lions as they became the first Australian provincial side to post a win since Queensland beat John Dawes' 1971 Lions team.
"You saw their reaction at the end, you saw what it meant to them on the pitch. We were in the dressing room at the end and their guy came out to me and said, 'I could retire now'," revealed England lock Parling, a second half replacement at Canberra Stadium.
"He said it's the biggest game he's ever going to play - it meant that much to them. I thought they were outstanding and they showed a tremendous amount of fight and we just didn't match it.
"They were over the moon, so fair play to them. They were playing as if it was the biggest game of their lives and we didn't match that aggression - we need to show more than we did.
"It was not one to remember, that's for sure, and now we just want to make this right. It hurts, but there are some big games around the corner and we can't afford to mope around for too long."
First chance to do that will rest with the first Test team in Brisbane on Saturday. The team will be announced on Thursday afternoon in Australia and Parling, like everyone else in the touring party, wants to be involved.
The Lions haven't won a Test series since 1997 and the 125th anniversary tour this summer would be the perfect time to set the record straight. The Qantas wallabies, of course, will have other ideas and are bound to have been boosted by the Brumbies' victory.
"After you lose any game the thing you want to do most is play again as quickly as possible. I'd love to be involved at the weekend," added Parling.
"We have a massive game on Saturday and we need to pick ourselves up and get back on the horse. We need to face this and get on with it."
"It's very frustrating to lose and we certainly know that we've got to get better. But there are big games coming and we can't have our heads down - not just for the games, either, we've got to get ourselves back up for the environment and for training and go again."