Tonight's win was Wellington's ninth on the bounce and success in Magpie country this week would give them a perfect 10 for the campaign.
With Ardie Savea, Brad Shields and Victor Vito, Wellington boast the best all-round loose forward unit in the competition and those three were instrumental in their success against Auckland.
Wellington were first on the board in the try-scoring department after some good work at the breakdown from Savea saw the Lions win a turnover and some quick distribution created a hole for Shaun Treeby who burst in to space and flew 50 metres to score.
Treeby's try added to the earlier efforts of five-eighth Lima Sopoaga, who booted three penalties in the opening 26 minutes, as he ticked past 100 points for the campaign.
Sopoaga then went close to scoring himself as halftime approached but was denied by the TMO before the returning Api Naikatini grabbed a five-pointer only minutes later when the Lions rumbled over from a lineout.
It was a nice reward for Naikatini, who had missed all of the ITM Cup to date with a broken arm, and his score allowed the home side to take a comfortable 21-6 lead to the break.
Normal service continued in the second spell as Sopoaga knocked over another penalty before Savea snaffled more ruck ball to bolt through a gap and score.
At 31-9 with half an hour still to play, the game looked safe and it was the ideal environment for All Blacks wing Cory Jane to return to the rugby field after he suffered a severe knee injury in February.
Jane was brought in to the contest at halftime and although play didn't come his way during the opening stages of the second spell he would have just been pleased to be out there following his lengthy rehabilitation.
As Auckland attempted to the chase the game their error rate mounted, while they struggled to make an impact at the breakdown, which didn't provide their backs with any quick ball.
Young outside back Melani Nanai then made matters worse for the Aucklanders when he was sent to the sin-bin in the 66th minute for an off-the-ball shoulder charge.
Playing against Wellington with 15 players has been tough this season, let alone taking them on a man down and eventually the extra body paid off for the Lions when Motu Matu'u scored in the 71st minute to lock up the bonus point.
Auckland replacement Nathan Vella scored in the dying stages for Wayne Pivac's side but it did little to influence the result.
The loss was damaging for Auckland, who missed out on a bonus point, as they could now be overtaken for second place - and a home semifinal - on the ladder by Canterbury in the final stages of the regular season.
Wellington 38 (Shaun Treeby, Api Naikatini, Ardie Savea, Motu Matu'u tries; Lima Sopoaga 4 pen, 3 con)
Auckland 16 (Nathan Vella try; Simon Hickey 3 pen, con)
HT: 21-6
