The Bay of Plenty Steamers' second-half blues reared their ugly head again last night, gifting one of the worst Auckland teams in living memory an undeserved 25-20 Air NZ Cup win at Rotorua International Stadium.

It had been a gilt-edged opportunity to nail the Super 14 franchise, with the Steamers ahead 13-3 at halftime and 7200 spectators baying for Auckland blood.

Compounding Auckland's plight were serious injuries to All Blacks Daniel Braid (ankle) and Joe Rokocoko (hamstring), and first-five Lachie Munro (dislocated arm) inside the opening half. They had also been reduced to 14 players after with lock Stan Haukinima was sinbinned for persistent infringing around the breakdown.

But rather than deliver the killer blow everyone had anticipated, the insipid Steamers got lost and let Auckland back in, bashing their way back into the game through their forwards, who then set their slick backline running for four second-half tries.

The matchwinner was freakish, with left winger David Smith throwing out a leg to fly kick a Kelly Haimona grubber on halfway. The ball bounced into the clear, was kicked again before replacement openside flanker Ono'sai'i Auva'a dived and skidded over the tryline to break the 20-all deadlock.

The ball didn't bounce the Steamers' way in the second half and they got the stiff end of some knock-ons ruled OK by referee Josh Noonan.

Standing out like a beacon was the patchy second spell start by the Bay. It was also there seven days earlier against Otago but this time it cost the match.

Blindside flanker Luke Braid, who had a stormer, said it was a game they let go. "We're real disappointed," said Braid, who played 77 minutes before limping off injured, although he didn't limp quick enough for Bay of Plenty to suffer further ignominy, penalised for having 16 players on the park.

"Our field position and kicking didn't go as well in the second half but big ups to the boys, it was a real hardy effort, just real disappointing."

In what was billed the Battle of the Braids, Luke got the early points with a decent front-on driving tackle on his older brother Daniel early in the game.

"He sort of turned and no one came in to set on him so I picked him up. On the way back down he gave me a shove and let me know he wasn't happy!"

It was a small personal high on an otherwise gutting night for Bay of Plenty.

Auckland had equalled the scores in just 10 minutes of the second spell as the Bay struggled to put their words into action.

Talk at halftime was to keep doing the same things, said Braid. "Whatever was called, to stick to the plans and stick to the maps. We did it sometimes but if we were more consistent with it, we would've come up with the win.

"We should've really beaten this team."

The Steamers talked during the week about starting with enthusiasm after halftime, and the coaches even made a bold move in injecting fresh legs from the bench much earlier than in previous matches.

Aidan Kuka replaced John Moore at lock and went within a whisker of scoring following a Ruki Tipuna free-kick dash. The near miss eventually became a converted try for captain Tanerau Latimer with Auckland running out of defenders, with Mike Delany converting to give the Bay a useful 20-13 lead.

But the blue and whites dug deep and Auva'a dotted down with less than 20 minutes to go. Ben Atiga converted, and with the scores tied, the two teams settled down to grind out the closing stages until Auva'a, showing impressive speed, slid over for the decisive try.

Bay of Plenty picked up a point and is still inside the top four but should be overtaken by Hawkes Bay, who play Counties tomorrow.

Scorers:

Auckland 25 (David Smith, Paea Fa'anunu, Onosai'i Auva'a 2 tries; Lachlan Munro pen, Ben Atiga con) Bay of Plenty 20 (Colin Bourke, Tanerau Latimer tries; Mike Delany 2 con, 2 pen). Halftime: 3-13.