It was a day when little could go wrong for the former Australian international who dominated the attacking circle.
Avellino, shot accurately, took almost every rebound that came her way and fed the ball cleverly to shooting partner Julianna Naopu when needed.
Southland centre and skipper Wendy Telfer was solid all round the court while wing defence Kylie Young was another prominent figure in Southland's success.
Telfer said the team were driven by a hunger to end 49 years in the wilderness.
" We just had so much passion, we got better and better through the tournament.
"It means a lot to win this title, we haven't been up there for a long time."
Southland sealed the title with a six-goal spurt in the first quarter from which Auckland Waitakere failed to recover from.
"We just got off to slow start," Auckland Waitakere defender Rachel Rasmussen said.
"We tried to peg it back but at the end of the day we couldn't. We just made too many errors throughout the court."
From 16-10, Southland more than doubled their score in the second quarter to 33 while a strugling Auckland could only sink seven attempts.
Although Auckland Waitakere outscored Southland 15-9 in the third quarter there was too much left to do in the final quarter.
Southland capitalised on Auckland Waitakere's growing desperation with Avellino confidently putting shots up at every opportunity and potting them more often than not.
In the playoff earlier for third placing, Otago beat North 56-53.
