The ACT Brumbies have won a see-sawing battle against the Highlanders, continuing to find their Super Rugby Pacific form with a 27-21 victory in Dunedin.

The visitors were leading by two points before hooker Lachlan Lonergan sealed Saturday's win with a 75th-minute try after his team mauled the ball over the line.

Five-eighth Noah Lolesio converted the try to push it out to a match-winning margin.

Highlanders playmaker Sam Gilbert was able to salvage a bonus point with a successful penalty kick after fulltime.

It was the Brumbies' third successive win over the Highlanders although they hadn't won at Forsyth Barr Stadium since 2013.

Skipper Ryan Lonergan was pleased with his team's second-half effort to secure the win, which followed a battling 22-19 victory over the Western Force.

"We still had a good look at ourselves after that Force game, we got the win but we weren't happy with our physicality and our breakdown," the halfback said.

"Even the first 20 minutes here, we were still a bit lazy in that area and then we flicked the switch and we started to muscle up in that area and we started to play a bit of footy."

The home side took an 11-7 lead into halftime after opening the scoring through a penalty strike by Gilbert and then a try to Nikora Broughton.

The No.8 capitalised on a Brumbies error and kicked the ball into the in-goal, winning the race to touch down.

The Brumbies opted against taking a penalty kick and built on their phases in attack before being rewarded with a try in the 23rd minute to fullback Tom Wright.

The visitors cleaned up their game in the second half, particularly around the breakdown, and were first on the scoreboard when winger Corey Toole used pure pace to race around the defence.

Their lead was out to 17-11 after Lolesio added the conversion and then another penalty.

But the Highlanders kept coming and were back in the lead after flanker Billy Harmon dragged five Brumbies defenders along as he stormed over from 10 metres out.

The Brumbies kept their composure and went in front 20-18 in the 65th minute off the boot of Lolesio.

Coach Stephen Larkham emptied his bench and came up trumps through Lonergan's effort to give his team their third win from four games.

The Brumbies do have some injury concerns with prop Blake Schoupp (shoulder) and centre Len Ikitau (leg) both forced off late in the first half while winger Andy Muirhead suffered a broken nose and flanker Tom Hooper a black eye.

While happy to get the win, Larkham felt there was still plenty of improvement ahead.

"It's a step up from last week - the lineout last week was pretty abysmal and this week slightly better so we're improving at least but from a forwards' carry perspective they really dominated tonight," he said.

"A few mistakes from the backs at the back end of the game but the forwards were really outstanding."