British & Irish Lions head coach Warren Gatland admitted his frustration after the shock 14-12 defeat to the Brumbies at Canberra Stadium.
The tourists, who were forced to field a makeshift three-quarter line that included the recently-arrived Billy Twelvetrees, Brad Barritt, Christian Wade and Shane Williams - struggled for fluency in the first period and were lucky to go into half-time just 8-3 down.
A dressing down during the interval had some impact as the Lions fought their way back into contention - but Stuart Hogg twice struck the post with penalties and that proved crucial in the end as the comeback fell short.
"We didn't have the urgency and intensity that we needed in the first-half. We are disappointed," said Gatland, whose squad had won five games in succession.
"All credit to the Brumbies. They played well, they frustrated us and it was a tough day at the office.
"It's a part of being on tour, regrouping. You have a bit of a knock, you take your disappointment and it is how you respond to it. A lot of us have been through it in the past - you just get back on the horse.
"We have been building nicely, there has been a lot of momentum. Maybe it's sometimes not the worst thing to take a bit of a knock and get a bit of a reality check, and we had that today."
Having conceded a try as early as the fifth minute, when Tevita Kuridrani broke two weak tackles and touched down to the delight of home fans, Gatland admitted he and the rest of the coaching staff dished out some stern words at the break.
The New Zealander added: "We made a few changes and gave them a bit of a rocket at half-time. We were a bit flat in that first half and played too much rugby in our own half. We probably needed to be smarter and play more territory. It was a tight game with a lot of kicking in the game.
"Sometimes it's happens. They put us under pressure (in the lineout) and a couple went astray. Those are just a few things we need to work on over the next couple of days.
"We spoke about whether to let the players who were on in the first half work their way through it and of course we've got to think about Saturday because a few of them will be involved then. It was a tough decision and I think the guys who came off the bench gave us a chance.
"A lot of players will be disappointed but we've got to take it on the chin and start focusing on the first Test on Saturday. We'll go back and have a look at the tape and the preparations need to start for Brisbane.
"We came here thinking we were on the right track and I think we've taken a bit of a backward step tonight after a really good performance against the Waratahs. The Brumbies frustrated us and I thought it was a tight game with a lot going on at the breakdown."
On the ongoing injury crisis that includes concerns over the likes of Brian O'Driscoll, Jamie Roberts, Manu Tuilagi, Tommy Bowe and George North, Gatland said: "We've picked up a few injuries.
"It's unusual for so many backs because usually it's the attrition of the forwards - especially the loose forwards. It's quite strange from that point of view."