The tourists committed the same errors that marked their first two tour outings, and this time they were made to pay for their shortcomings by the strength of the Maori.
With a host of All Blacks in the squad, Matt Te Pou's men were superior in most departments and deserved their first victory over the Lions in seven attempts stretching back to 1930.
Skipper Brian O'Driscoll scored with six minutes to go to give the Lions hope - Stephen Jones' boot provided the rest of their points - but critical late errors halted the comeback.
Pre-match talk centred around the tourists' juggernaut front row of Andrew Sheridan, Steve Thompson and Julian White - the heaviest in Lions history - but Sir Clive Woodward must have been disappointed with its impact.
Scrum time was expected to provide fireworks and the first after just four minutes did not disappoint, the two front rows having to be separated before referee Steve Walsh spotted a Maori punch and gave the Lions a penalty.
The niggle continued at the breakdown and the deadlock was not broken until the 14th minute when a thrilling scrum-half break from Matt Dawson ended in a penalty which Jones nudged between the uprights.
Maori fly-half Dave Hill responded in kind to level the score and they threatened to add to their tally with a try, only to be restricted by some unusually poor handling in the backs.
The Lions were being out-muscled at the breakdown and looked rattled, gifting another three points to Hill's boot, but then settled for a brief period with Jones landing a penalty.
Their problems increased two minutes before half-time when prop Sheridan was sin-binned for an attempted punch on centre Rua Tipoki and the appearance of Maori favourite Carlos Spencer from the bench gave the home side fresh impetus.
Spencer - playing his last game for the Maori before joining Northampton - nearly set up a try with a cheeky kick which was well marshalled by Josh Lewsey before a Luke McAlister penalty gave Te Pou's men a 9-6 lead.
Full-back Leon McDonald was driven over with Spencer involved in the build-up, and McAlister added the conversion and another penalty.
The Lions finally pounced in the 72nd minute when O'Driscoll ran onto Jones' flat pass and raced over with the Wales fly-half slotting the extras, but they ran out of time to complete the fightback.