New All Blacks prop Saula Ma'u was overcome with emotion after making his Test debut in Saturday's 41-35 victory over the British and Irish Lions in Johannesburg, describing the moment as a "dream come true."

The 26-year-old Highlanders and Otago forward took the field as an injury replacement in the 60th minute, called up to the squad after Ollie Norris was ruled out. Speaking to media after the match at Ellis Park, Ma'u said he was still processing the experience.

"This was always a goal of mine to one day to play for the All Blacks," he said. "Coming into camp last week just feels crazy to be in that environment. The boys making me feel welcome, the coaches just getting me up to speed and it's a dream come true and obviously I want more of it ... we'll see what happens."

The Tongan-born forward, officially All Blacks no 1242, was visibly emotional as he spoke about his family and faith.

"Thank you to the heavenly Father for, you know, the blessings that he gave me to wear the black jersey and obviously my friends and family back home, my partner, Nia, mum and dad," he said. "Just grateful for the coaching staff, for the All Blacks giving me a chance to represent my family, my friends and my village back home. Hopefully, I made them proud."

Ma'u, who was called into the squad last week, said he hoped his performance had done justice to those who supported him along the way. When asked about the fate of his first All Blacks jersey, the debutant had a light-hearted response.

"Probably going to sleep with it tonight," he joked. "No, going to keep it in a safe place."