He also heads the statistics for most clean breaks with eight and is 30 metres clear with 407 metres carried.
Stevenson told SKY Sport his form through the first three weeks of the competition was down to 'time in the saddle'.
"Getting consistent game time, and I back myself to play an expansive game, and I'm just going with confidence at the moment.
"Our backline is pretty good to play with as well. It's exciting times."
The team had been together for some time bounding and gelling.
"We've had the same team for three or four years now and, I think, it's all clicking now. We've got that belief that we are a top four team, so, hopefully, we can continue this good run."
Stevenson made seven carries against the Highlanders, scored two tries, beat five defenders and made 107 metres with his running.
Stevenson said the side's patience was crucial to Friday's win over the Highlanders.
"We knew we were only a couple of phases off in the first-half. Our handling let us down, so we knew if we could hold onto the ball for three or four phases, build some pressure we could get some treats in the end and luckily we got a few tries in the second half."
Stevenson, 26, made his first-class debut for Waikato in 2015 and played 11 games over two seasons before transferring to North Harbour in 2017. He has made 53 appearances for the Albany-based side.
After playing in the New Zealand Under-20 side in 2016, the same year he first appeared for the Chiefs, he was selected for the first of his 12 Māori All Blacks appearances in 2017.
He played for the Barbarians in 2019 and toured with the All Blacks XV in Ireland and England last year.
The Gallagher Chiefs take on the Melbourne Rebels at 4.35pm, Saturday 18 March, at FMG Stadium Waikato.