Ahead of the clash in Hamilton, Ireland's captain Bundee Aki placed a number 11 Ireland jersey on the pitch before an emotional haka performed by the Māori All Blacks.
Wainui, a key member of the Māori All Blacks who wore the number 11 jersey during his career, was killed when his car hit a tree at McLaren Falls Park near Tauranga on 18 October last year.
He was just 25, capped 10 times for the Māori All Blacks, and it was the first time his teammates had played since his tragic loss.
Wainui's wife Paige and their two children, son Kawariki and daughter Arahia, walked onto the field and took the jersey prior to the match.
RNZ's sports commentator Jamie Wall said it had been a "lovely touch from the Irish skipper".
It mirrored a similar moment back in 2016 when the Māori All Blacks paid their respects to the late Anthony Foley, when they faced Irish provincial giants Munster for the first time at Thomand Park, Limerick.
Before performing the haka, captain Ash Dixon had marched to the halfway mark and laid down a Māori All Blacks jersey with the Munster legend's initials, "AF" on the back, before retreating back to his side.
Following the haka, Dixon presented it to Foley's sons, a move that touched Irish hearts.
Foley had played 13 years for Munster, and coached them from 2014 until his sudden death in October. He was 42.