With the defending champions having next weekend off, the winner of the showdown in Wellington will have the chance to go top of the New Zealand Conference heading into the home stretch of the competition.
If that team is to be the Highlanders, there will need to be a drastic turnaround after an uneven performance. They had just returned from a South African sojourn and the fatigue of that trip began to show as the game wore on, with the Lions' slow and steady approach beginning to reap reward.
The visitors had all of the ball in the opening half but found themselves in a huge hole at the break. Aside from a pair of brief spells right after the kick-off and immediately before halftime, the Highlanders saw little possession and were left to soak up a lot of pressure.
There was a lack of imagination from the Lions and they rarely made it over the advantage line. In contrast, the Highlanders seemed content to make their tackles and strike with pace when they earned an opportunity. Richard Buckman's double emphasised that, particularly a second that came after Phil Burleigh's seemingly innocuous but brilliantly weighted clearing kick into space. The wing's speedy work looked like it would be all the Highlanders needed, and the game seemed decided when Gareth Evans crossed on the stroke of halftime after excellent work from Malakai Fekitoa and Ben Smith.
But an alteration in strategy from the Lions, with a greater emphasis on pick-and-go, added spice to the second half, especially after Francois de Klerk burrowed over.
All the work the Highlanders' defence was having to do eventually started to tell, a problem exacerbated by the sin-binning of Chris King for a stray elbow. The Highlanders were beginning to be run ragged and Lionel Mapoe's try midway through the half had the Lions threatening a late salvo.
When Armand van der Merwe converted a nice lineout movement to pull within six points, the game looked like it could be decided by the final play. And so it proved, with Jantjies unable to add the extras from Courtnall Skosan's late try.
The Highlanders did break early from the line, and the Lions argued for a retake, but Angus Gardner instead blew the final whistle.
Highlanders 23 (R. Buckman 2, G. Evans tries; H. Parker con, pen, drop goal)
Lions 22 (F. de Klerk, L. Mapoe, A. van der Merwe, C. Skosan tries; M. Boshoff con).
Halftime: 23-0.