The Sunwolves may have opened their 2018 Super Rugby season with a loss Saturday at Prince Chichibu Memorial Rugby Ground, but there was plenty in their 32-25 defeat to the Brumbies to show they are going to be competitive in the Australian Conference.

Willie Britz, Kazuki Himeno and Lappies Labuschagne battled tirelessly up front, while Lomano Lemeki and Hosea Saumaki made their presence felt on the wings as Jamie Joseph's side defied their limited build-up.

"There are a lot of disappointed faces in the changing room but I am really proud of the team," Joseph said.

Captain Yutaka Nagare said the Sunwolves had "let the Brumbies off the hook," but said the game had been a "fruitful experience" with the attacking mindset a real positive.

Two tries shortly after the break -- one highly fortuitous -- eventually proved to be the game changer after the Sunwolves had gone into the break 19-15 up. Joseph's side can take some satisfaction from taking a bonus point off the two-time Super Rugby champions by virtue of losing by seven points or less.

"The feeling is one of relief. We were challenged by a very good Sunwolves side," said Brumbies coach Dan McKellar. "But we showed resilience and worked hard to grind out a win in a tough environment."

Following an early penalty by Christian Lealiifano, the Sunwolves struck twice in the space of 10 minutes through Saumaki and Timothy Lafaele to go 14-3 up.

Saumaki was to add a second as the Sunwolves took the game to the visitors, keeping ball in hand and exploiting weaknesses in the Brumbies' defense.

But the inability of the Sunwolves to clear their own line and their tendency to give up penalties at crucial times was exploited with Lachlan McCaffrey and Kyle Godwin both crossing the chalk either side of Saumaki's second five-pointer.

With the wind at their backs in the second half, the hosts needed to ensure they kept the momentum going from the start.

But an awful piece of luck saw Tevita Kuridrani go over just a minute into the second stanza after a pass from Nagare hit the post and bounced into the hands of the Wallabies center.

Former Kyuden Voltex hooker Josh Mann-Rea increased the lead 11 minutes later following a well-executed driving maul before Hayden Parker brought the Sunwolves back to within five points with a 64th-minute penalty.

The Brumbies, however, added a fifth try through Tom Banks following some good soft hands from forwards and backs alike, a score that ensured the Sunwolves had too much to do in the final minutes.

The Sunwolves' decision to kick for goal after the hooter may have met with a mixed reception from the crowd but Parker's left foot ensured a bonus point.

"If we had scored a try it would still have been just one point," Joseph said of the decision.

McKellar said his team's ability to adapt had been key.

"We didn't do well in the first 20 and turned over possession and the Sunwolves took advantage," he said. "The message at halftime was to go back to playing simple and clean. It wasn't perfect but it was better."

Joseph, meanwhile, said the Sunwolves, who had just four weeks of preseason and no warm-up game, would learn from the experience.

"You can practice things till the cows come home, but it is very different when you are under the pump and under pressure."