VIDEO: Brumbies 'hurt' by critical moments
The Brumbies were outscored six tries to two and had to settle for a 17-43 defeat in Dunedin.
The Canberra side trailed 10-15 after a very tight 60 minutes. However second-half lapses swung momentum in the Highlanders' favour.
The New Zealanders – with 14-man on the field after Lima Sopoaga was given a yellow card – scored three tries in 10 minutes, including an intercept try by Waisake Naholo.
"There are a number of things that went wrong during the game," Brumbies head coach Dan McKellar told reporters after the match.
"Our line-out execution let us down at critical moments within the game.
"At 15-10, we were attacking really nicely and we go the long pass and [Waisake] Naholo grabs an intercept and goes the length of the field,” he said, adding: "It changes the game and [then there was] another turnover try that Ben Smith scored.
"That's what hurt us."
"Think what my players learned is that room for error in those key moments is small when you play in [New Zealand],"
The defeat means that they are now six points behind second-placed Rebels in the Australian conference.
Brumbies' next Super Rugby fixture is against the Jaguares at the GIO Stadium on Sunday, April 22.