All dream rides have to come to an end, as the Bay of Plenty Steamers found out yesterday at Eden Park.

Their four-game Air NZ Cup-winning streak ended at the hands of a much-improved Auckland side, beaten 29-15.

The weekend's results saw the Bay - who went into round five as the competition leaders and the only unbeaten team - passed by Canterbury and Southland who they play over the next two weeks.

After accounting for Waikato, Wellington, Counties-Manukau and Northland in previous rounds with a dependable "territory game", the Steamers finally came unstuck on a wet and slippery Eden Park.

Auckland had all the answers for the Bay yesterday, positioning men back to nullify the kick gains of five-eighth Mike Delany, Phil Burleigh and halfback Junior Poluleuligaga.

On attack, the home side cracked Bay's defence four times, after Bay had previously let through only three tries in 320 minutes of rugby.

Poluleuligaga said the reasons for the Steamers' first loss lay before him and his opposite Taniela Moa.

"I was looking forward to the test against Taniela," said the Manu Samoa international.

"We're pretty much similar build but you know, if you've got a pack that's going forward and giving you the ball on a platter, the halfback's definitely going to have an easy ride and that's what he had. He had time to run with the ball."

And with Moa kicking or running, the Auckland forwards dragged in the Bay defenders which freed up space out wide for the likes of winger Joe Rokocoko, centre Isaia Toeava and second-five Benson Stanley who frequently went over the advantage line, even if they did spill the ball a few times in the wet.

Poluleuligaga felt the Auckland team had also done their homework before the game.

"We came here looking to play our territory game but they covered it well and the options weren't there to kick because they had players in the areas. Their body height in general, going into rucks and stuff, was also much lower."

The re-introduction of Auckland's four All Blacks - John Afoa, Jerome Kaino, Rokocoko and Toeava - also didn't help the Bay's cause, according to Poluleuligaga.

"Early on in the season, Auckland didn't have their All Blacks and they weren't playing that well but they're just like any other team, once they have their All Blacks they really lift the intensity and attitude."

For the first time this season the Bay struggled to consistently control the ball and territory and at times they looked rattled and confused.

Their efforts in trying to catch high balls were terrible with fullback Zar Lawrence, the worst of the Bay's offenders, guilty of not even getting under some.

Auckland had one hand on the John Drake Boot memorial trophy when they had two converted tries on the board inside the first 20 minutes.

Rokocoko scored the first after fullback Paul Williams brushed off a Jason Hona tackle but the second was the result of a Bay bumble as a ball spilled out of a ruck and was passed to no one while Delany and Burleigh bumped into each other, allowing Bowden to force the ball.

Bay worked back into the game in the second 20 minutes with two Delany penalties and they were not totally shut out at 14-6 at the break, advancing to 14-9 seconds after the restart.

However, the injection of Jerome Kaino from the bench seemed to further lift the Auckland pack while Toeava laid on a sweet pass for Rokocoko to score his second try. Williams dragged over three Bay defenders for the bonus-point earning fourth try.

Bay of Plenty did finish on a positive note - Colin Bourke and Nigel Hunt combined in an 82m try after the final hooter.