Both the leaders Wellington and second-placed Bay of Plenty are four from four in the national provincial rugby competition after beating Southland and Northland respectively.
It was seven-all at halftime in Invercargill but Wellington pulled away to win by 26 points to 7.
The Lions scored early off a break by halfback Alby Matthewson from a Southland scrum turnover, the number nine scampering 30 metres to dot down. First five eighths Piri Weepu converted but Matthewson was sin-binned as Southland applied relentless pressure on the Wellington line, which finally told in the 37th minute. After being camped in the Lions' half and some valiant defence, hooker David Hall crossed for the Stags.
However Wellington ran in three second half tries for the bonus point win as they introduced their All Black forwards Neemia Tialata and Chris Masoe.
Corey Jane scored the second then Masoe and Tamati Ellison got the others.
In Whangarei Bay of Plenty scored the only try in the second half to win 15-10.
It was 8-7 at halftime before Bay of Plenty wing Lance MacDonald scored the match-winner in the 49th minute.
Northland threatened throughout the second half in front of a 14,000-strong crowd but the Steamers' defence held.