ACT Brumbies half back Nic White said "Test match intensity" was on display as his side upset the highly-rated Blues to send an early message in the Super Rugby Pacific season.

Sunday's wild encounter in Melbourne brought 45 points in the first half but somehow none in the second, with proceedings tightening up drastically as the Brumbies dug in to take the 25-20 win.

Avenging their 2022 semi-final defeat, Stephen Larkham's men never trailed but were seriously tested on their way to a statement win that firmed up their case as one of the league's top sides.

Now 2-0, the ACT relied on their set-piece dominance to control the match and had the Blues on the back foot from early on, indicated by them winning a lop-sided penalty count 16-8.

The Brumbies could have led by more at halftime after dictating the play but were plagued by defensive lapses and sub-standard ball security.

The Auckland outfit had the better of the second half but rarely threatened their opponent's stubborn line, with line-out struggles costing the ACT a chance to secure victory earlier.

White, who entered off the bench with fellow Wallaby Noah Lolesio to help close out the win in the final half hour, said the high-level encounter had brought the best out of his side.

"So many points in that first half - it was just Test match intensity," he told Channel Nine.

""Honestly, every breakdown, every carry, every tackle was just absolutely everyone giving everything.

"It was good footy, a really tight contest and we know we're going to get that against the Blues; they compete for everything."

The ACT's rolling maul fired on all cylinders and produced two tries in the first half, with the first - a penalty try - leaving Blues prop James Lay in the sin bin.

He was the second Blue yellow-carded but the two-man disadvantage did little to stop them grinding their way into the game, scoring through Ricki Riccitelli and later via a powerful run from Tom Robinson.

The Blues threatened late but the Brumbies proved equal to the task, with White later saying they'd avoided flashbacks to last year's heartbreaking 20-19 semi-final loss, and had instead backed their system.

"We weren't really thinking about that (semi-final), and that's a good sign for us because we're just concentrating on the next job in that next moment," he said.

"We could have taken three but we chose to put them down here and make them go the length of the field, and really strangled them.

"We kept on competing and competing ... holy dooley they're a good team and boy they made us work for it."

Skipper Allan Alaalatoa left the game inside the first 10 minutes with a head knock and didn't return.

Blues captain Dalton Papalii agreed with White's assessment of the gripping match's intensity.

"We (created) a rivalry over the last year and even coming into this year, we knew this was going to be a big match," he said.

"We knew we were going to come in and get a Test-match footy calibre game.

"I think it was out there and it goes to show that it was a grudge match til the end."

Blues 20 (Ricky Riccitelli, Tom Robinson tries, Beauden Barrett 2 con, 2 pen) ACT Brumbies 25 (Andy Muirhead, Lachlan Lonergan tries, penalty try, Ryan Lonergan 2 pen, con)
HT: 20-25

Referee: Ben O’Keeffe
Assistant Referees: James Doleman, Angus Mabey

1. Joshua Fusitu’a 2. Ricky Riccitelli 3. James Lay 4. Patrick Tuipulotu 5. Cameron Suafoa 6. Tom Robinson (Adrian Choat) 7. Dalton Papalii 8. Hoskins Sotutu 9. Finlay Christie 10. Beauden Barrett 11. Caleb Clarke 12. Roger Tuivasa-Sheck 13. Rieko Ioane 14. Mark Telea 15. Stephen Perofeta

Reserves: 16. Kurt Eklund 17. Ofa Tuungafasi 18. Marcel Renata 19. James Tucker 20. Adrian Choat (Anton Segner) 21. Taufa Funaki 22. Bryce Heem 23. Jacob Ratumaitavuki-Kneepkens

ACT Brumbies:
15: Tom Wright, 14: Andy Muirhead, 13: Len Ikitau, 12: Tamati Tua, 11: Corey Toole, 10: Jack Debreczeni, 9: Ryan Lonergan, 8: Pete Samu, 7: Rory Scott, 6: Rob Valetini, 5: Cadeyrn Neville, 4: Nick Frost, 3: Allan Alaalatoa (c), 2: Lachlan Lonergan, 1: James Slipper

Reserves: John Ulugia, Blake Schoupp, Rhys van Nek, Darcy Swain, Luke Reimer, Nic White, Noah Lolesio, Ollie Sapsford