The Lions held off an impressive Auckland fightback to secure a hard-fought victory at Eden Park.
Despite wasting a host of chances, the tourists led 14-3 at half-time with three penalties as well as a late try from Welsh flanker Martyn Williams.
But Brent Ward's second penalty as well as an Isa Nacewa try after the break put Auckland within a point.
Ward then missed a difficult kick while Ronan O'Gara added three points and the Lions were able to hang on.
It was always going to be a difficult contest for the Lions, coming just three days after losing the Test series against New Zealand and against their strongest midweek opposition of the tour.
They showed plenty of intent and fight but just could not take full advantage of Auckland's mistakes, especially in the first half, to claim an even greater margin of victory.
But the midweek side, led by Ian McGeechan, will take a lot from the fact that they have ended the tour unbeaten.
Auckland looked to run the ball at every opportunity but they conceded plenty of possession to the Lions with the help of a desperate line-out and some hesitant play from fly-half Tasesa Lavea.
The Lions put the first points on the board with Charlie Hodgson, unlucky not to be in the Test squad, kicking three points on four minutes.
They should have added more but, as so often on this tour, the Lions attacking play lacked the required precision.
Auckland could have taken the lead after the Lions infringed on three separate occasions, but they bravely opted for old-fashioned tap penalty moves rather than kick for goal.
They almost crossed on 21 minutes but Martyn Williams and Matt Dawson combined superbly to hold up prop John Afoa over the line.
Hodgson had to leave the field after picking up an injury in that incident and his replacement Ronan O'Gara added another three points on 27 minutes.
But Auckland quickly replied with three points of their own through Brent Ward.
The Lions then almost crossed for the first try of the game, but Williams was taken out off the ball right under the posts as he looked certain to score.
Despite it being so close to the line, referee Steve Walsh decided not to award a penalty try or issue a yellow card.
Ben Kay showed his frustration in a scuffle with Sam Tuitupou, which forced Walsh to reverse the penalty, while the Leicester lock left the pitch with a nasty-looking shiner.
O'Gara was able to add another penalty and the Lions finally crossed in the closing stages of the first half through Williams, following a wonderful jinking run from the impressive Mark Cueto, to make the score 14-3.
Ben Kay left the field after taking a blow to the face
Dawson tried to get the Lions moving at the start of the second half with some trademark sniping runs but slowly Auckland came back into the game.
Gordon D'Arcy was penalised for lying over the ball before Ward reduced the deficit with another kick, and it was not long before the Lions conceded again.
Lavea started to find the gaps and after his break and some neat hands in the backs, Nacewa crossed. Ward's conversion made the score 13-14 to really start the pulses racing.
Boosted by the score, Auckland raised the pace of the game and the Lions were forced into some desperate defending.
The Lions conceded another penalty and Ward had the chance to edge his side in front with 11 minutes to go but his kick came back off the post.
O'Gara kicked over on 75 minutes to put some space between the sides and the Lions were able to hang on for the victory despite some intense Auckland pressure.
Auckland: Brent Ward; Isa Nacewa, Ben Atiga, Sam Tuitupou, Joe Rokocoko; Tasesa Lavea, Steve Devine; Saimone Taumoepeau, Semisi Telefoni, John Afoa; Brad Mika, Bryce Williams; Justin Collins (captain), Daniel Braid, Angus MacDonald.
Replacements: John Fonokalafi, Chris Heard, Kurtis Haiu, Jerome Kaino, Taniela Moa, Isaia Toe'ava, Gavin Williams
Lions: Geordan Murphy; Mark Cueto, Will Greenwood, Gordon D'Arcy, Denis Hickie; Charlie Hodgson, Matt Dawson; Graham Rowntree, Gordon Bulloch (captain), John Hayes; Simon Shaw, Ben Kay; Jason White, Martyn Williams, Michael Owen.
Replacements: Andy Titterrell, Matt Stevens, Brent Cockbain, Martin Corry, Chris Cusiter, Ronan O'Gara, Shane Horgan.