A cheeky piece of improvisation by rising talent Orene Ai'i clinched two time winners Auckland a valuable 18-15 win over Super 12 rugby tournament favourites ACT Brumbies here Friday night.

The Blues, playing with more cohesion and determination, fought back from a 10-0 deficit in the opening 13 minutes and 15-13 down 10 minutes from time to clinch an important away victory to launch their season.

And it was the precocious skills of 20 year-old flyhalf Ai'i who engineered the match-clinching try.

Ai'i, who won a points decision over Wallaby incumbent flyhalf Stephen Larkham, grubber kicked ahead on the halfway line, regathered and found winger Doug Howlett in support.

Howlett, who also had an outstanding game, passed to replacement forward Finau Maka who plunged over in the left corner to put Auckland ahead by three points.

It was a wholehearted performance by the Blues, who finished ninth last year and have lost many of their old guard All Blacks. But under the coaching of Gordon Hunter and Grant Fox they appear to be building towards more glory.

Rugby league convert Andrew Walker had an outstanding debut for the Brumbies, scoring their two tries and being tackled into the corner post when heading for his hattrick late in the second half.

His composure under the high ball and long-range kicking appear to make him an ideal acquisition for ACT at fullback.

Auckland effectively played for 30 minutes without a player after having three players, flankers Justin Collins, Troy Flavell and winger Howlett given a yellow card and 10-minute spells in the sin bin for hitting Larkham with late tackles.

South African referee Andre Watson was called on to use the video referee to adjudicate on two occasions and both times no try was awarded to each side.