Brumbies coach Dan McKellar is left ruing a passive early effort from his side and a missed opportunity to make up ground on their Super Rugby conference rivals after they lost 25-20 to the Jaguares in Canberra.
The Brumbies were the only local side to get a point from the round but on Sunday they blew a chance to make up more ground on the two teams above them in the Australian conference.
They were always in chase mode after trailing 13-0 early, with captain and lock Sam Carter saying his side was asleep in the first 20 minutes.
The Brumbies got back to within three points by halftime following two tries by fullback Tom Banks.
But their failure to post points when the Jaguares were down to 14 men early in the second half proved costly.
Five-eighth Wharenui Hawera salvaged a bonus point for the Brumbies with a penalty after the siren.
"I thought overall our first 30 minutes was passive. It just wasn't good enough," McKellar said.
"The last 10 minutes of the first half we managed to get possession, build pressure, maintain pressure and we scored two tries."
The Jaguares controlled possession for most of the time winger Emiliano Boffelli was in the sin bin for tackling Henry Speight in the air.
Shortly after he returned, centre Jeronimo de la Fuente crossed and five-eighth Nicolas Sanchez converted to put the Jaguares 10 points ahead.
The Brumbies pulled the deficit back to three with 13 minutes to go when winger Chance Peni escaped three defenders to score and Hawera converted.
But Boffelli atoned for his earlier indiscretion, crossing in the left-hand corner in the 71st minute for the match-clinching score.
"We just didn't take the opportunities when we had them," Carter said.
"I think we had four or five cracks and turned it over one or two metres from their tryline.
"We knew they were going to come out pretty hot, pretty passionate and start fast.
"We needed to be better in that first 20 minutes. There were too many mistakes even getting out of our end.
"We didn't execute when we had to - that was the issue tonight."
The Jaguares dominated the first half-hour, with centre Matias Orlando crashing over from close range after a patient 18-phase move.
Sanchez converted and kicked two penalties before the Brumbies finally woke up and applied pressure.
Banks crossed in the 35th minute from a Hawera pass and the two combined again on the stroke of halftime when the fullback pounced on a perfectly placed kick from his pivot.