Mrs Savea and her husband, Masina, were joined in the stands by her son's partner, Dawn, and newborn daughter, Cora.
"We were nervous and happy at the same time. We didn't know how he would go. But we were excited when he ran out in that All Blacks jersey. Everyone was so proud - his dad, his brother, all of us."
Savea's younger brother Ardie was part of the New Zealand sevens team which won its 10th world series title in London last month.
Mrs Savea and her family went back to the All Blacks' hotel afterwards to catch up with rugby's newest star.
"He was so rapt. He was happy that he scored a try and he said he was never expecting to get three. He owes it all to the team of guys that set him up."
Savea's parents always had faith he would be named in an All Black squad - but not at such a young age.
"We didn't think it would happen this quick," said Mrs Savea.
Despite his exhilarating first game on Saturday, Savea's parents still think there are areas he could work on.
"We still tell him he has to do this, and work on that. But I guess it's easy for us to sit and watch and tell him what to do.
"I know it's a lot different when they're out on the field."
The hardest part of watching her boy play was seeing the big tackles - both the hits on him and the ones he was behind.
"When he does a big tackle I always think, 'Oh, that's someone else's boy under there.' It does get us quite nervous when Julian is tackled. But it's okay when I see him get up again."
