Moana Pasifika had nothing to lose and everything to gain in the upset of the Super Rugby Pacific season.

Their speed of play and physicality proved too great for Australia's best finals chance, the ACT Brumbies, in their 22-32 loss.

Penalties, again, and individual errors took centre stage against the visitors to cost them four points in Auckland.

The contest began with heartbreak for Moana, as they lost their skipper 10 minutes into his 150^th Super Rugby game.

Sekope Kepu received a red card for a dangerous head-high tackle on Andy Muirhead. Before they then lost former Brumby Christian Leali'ifano for a HIA.

It took the Brumbies two minutes to capitalise off a line out set piece.

A rolling maul saw Connal McInerney cross for his second try of the season, before Noah Lolesio converted it to make it 7-0.

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From there, it was all Moana.

Back-to-back penalties on the line allowed Moana to capitalise, with three players left unmarked on the open side.

Willy Havili caught a cut-out pass and crossed in the 20^th minute to make it 7-5.

Multiple penalties around the ruck breakdown, to try and slow play, forced referee Michael Fraser to warn the Brumbies.

The ill discipline in defence cost the visitors, with Moana crossing again.

This time through Joe Apikotoa off a rolling maul, and a conversion by Leali'ifano - after passing his HIA - made it 7-12.

Brumbies skipper Allan Alaalatoa said it was a disappoint outing for his side.

"It was pretty disappointing from our end, we were probably outplayed tonight," he told Stan Sport.

"Probably out-enthused, so some great learnings for us.

"The bright side is we get another opportunity next week in finals. I'm unsure where we sit now, but we just need to regroup, stay connected and make sure we learn from tonight."

Things soon went from bad to worse for the Brumbies.

They did not heed to Fraser's warning and try-scorer McInerney was shown a yellow two minutes before the half-time whistle.

It was deva ju for Brumbies fans, as Moana kicked it into the corner for a line out, and again made no mistake with a rolling maul.

Jahrome Brown showed desperation on the line, forcing a collapse, and was the second Brumby to receive a 10-minute sin bin.

This made Ray Niuia's try a seven-pointer, leaving the Brumbies on the wrong side of a 7-19 scoreline.

The Brumbies knew they needed to get on the score sheet first during the second half.

With 13 men, they opted for a Lolesio drop kick to claw back three points. Until they gave away another penalty, and Leali'ifano claimed those three points back.

The Brumbies received a boost through a full XV, with McInerney and Brown able to return from the sin bin.

Back to full strength, and with re-enforcements from the bench, they turned to their signature rolling maul set piece.

Moana prevented the first, but the strength of the second proved too great.

Lachlan Lonergan crossed, and Lolesio put it between the posts, to make it a 17-22 game.

The five-point difference soon became an eight-point difference, as Moana's Leali'ifano capitalised on another penalty goal.

Alaalatoa praised Moana's game.

"They have strong ball carries, it's something that we spoke about before," he said.

"They probably dominated the collision tonight. The disappointing part for us was they took us at our own game, scoring a couple of maul tries there too.

"So, again, for us, it's a huge learning, but you can't take it away from Moana and the passion that they showed tonight."

Errors in Moana's 22 prevented the Brumbies from getting more points on the board, and allowed the home side to increase their lead.

Leali'ifano showed his experience with a 50:22 kick and it was this that put the final nail in the Brumbies coffin.

Moana earnt a scrum feed five metres out, and debutant Lotu Inisi crossed before their number 10 converted.

The visitors had the final word in their third straight loss through Pete Samu, leaving it 22-32.

The Brumbies will need to eliminate individual errors, and tighten their defensive discipline, in next week's quarter-final in Canberra, against their likely opponents the Wellington Hurricanes.

MOANA PASIFIKA 32 (Willy Havili, Joe Apikotoa, Ray Niuia, Lotu Inisi tries; Christian Leali'ifano 2 conversions, Leali'ifano 2 penalty goals) bt ACT BRUMBIES 22 (Connal McInerney, Lachlan Lonergan, Pete Samu tries; Noah Lolesio 2 conversions, Lolesio drop kick) at Mount Smart Stadium.