Christian Lealiifano has seen the Sunwolves up close and he believes Super Rugby experts need to start taking the Japanese team more seriously.
Last year's Australian conference winners were expected to smash the team that had won only three games in their first two seasons in Tokyo on Saturday.
Their only previous meeting in 2016 was a 66-5 thumping in favour of the Brumbies in Canberra.
Dan McKellar's team began the first leg of a three-week away stretch with a 32-25 victory, but not before the Sunwolves led at halftime and snatched a point with a last-gasp penalty goal.
"Teams have seen them play after today's game and with Jamie Joseph coaching them now, they're going to surprise a lot of teams," Lealiifano told AAP.
"The competition has to give them a bit more respect than they have previously because they're a dangerous team and will only get better."
The Brumbies co-captain produced a dazzling display in his first Super Rugby start since the 2016 quarter-final loss to the Highlanders.
The playmaker came off the bench in the corresponding game last year after making an inspirational recovery from leukaemia.
Lealiifano scored the first points against the Sunwolves by slotting a penalty goal, which took him past 800 career points in the competition.
He became just the second player in Brumbies history to achieve the feat behind Wallabies great Stirling Mortlock and the fourth Australian with only Mortlock (1036), Matt Burke (959) and Quade Cooper (844) ahead of him.
Lealiifano said he was pleased to carry on the form he showed playing for Irish club Ulster during the Super Rugby off-season, where he made 16 appearances.
"Obviously getting some footy under my belt was useful coming in and I just want to keep building on performances like today," Lealiifano said.
"It was pretty special to play a full game again and like I've spoken about before, I'm just very grateful to be back playing at all."
Australian Associated Press