Buoyed by finally breaking the Wellington line, the visitors took over the game in the third quarter, scoring three tries in the space of 10 minutes to snatch the lead from their hosts and then build their way to a 32-20 lead with 25 minutes to play.
Led by TJ Perenara in the No 9 jersey, the Lions didn't panic at falling behind, and continued to plug away on attack. Within the 10 minutes following the last of Bay of Plenty's try trio, Wellington themselves had scored two more converted tries and slotted a penalty.
With just two points the difference, the match remained there for the taking. However, with neither team able to do any more damage on the scoreboard in the final 15 minutes, Wellington held on for an opening round win, with both Savea and second five-eighth Riley Higgins grabbing two tries each.
In New Plymouth, Northland equalled their total wins from last season when they stunned Taranaki 13-11 in a scrappy contest. Northland didn't score a point until the 56th minute, but defended well and ultimately finished the better of the two sides.
In Blenheim, Tasman beat Southland 27-20. The perennial contenders were pushed right to the final whistle by the perennial strugglers, who had a strong second stanza after the hosts had built a 17-point halftime lead.
In the Farah Palmer Cup, Otago compounded the dismay for Taranaki fans as they piled on the points in a 55-15 win in New Plymouth, while Tasman toppled North Harbour 42-15 in Blenheim.