Mains, a former All Black coach, played in three unsuccessful challenges and also coached Otago four times when it challenged for the shield.
Each time the team come up short, and Mains said it was fantastic the Otago team on Friday night could finally grab a win after a 56-year drought.
''I sent Tony a text and just said to him, what a fantastic performance. They had an outstanding defensive pattern for the game which the players stuck to. Credit must go to the coaching team,'' Mains said.
''He is clever, is Tony. I saw that in him and felt he was the right guy for Otago. He has learnt very quickly.''
Mains has endured plenty of heartache to do with the shield over the years.
He was part of the 1967 team that lost 9-8 to Hawkes Bay in a cliff-hanger and then lost 16-12 to Canterbury in 1970.
''The law of averages would say in those close ones, one of them would be won by Otago. In 1967, we never thought about how long we hadn't had the shield. It was only 10 years. Sure, we wanted to have it, but it was just as much about winning the game for Otago.
''Over the years, we have had a lot of bad luck. And that was what it was. Just plain bad luck. Look at that game in 1994 when David Latta got penalised. There was probably half a dozen rucks that day that the same thing or worse could have been penalised.''
In the time he had coached, Auckland had a huge shield reign, and Otago challenged four times and came up short every time.
Mains said Otago had great teams in 1975, when it lost just two games, and in 1991, when it won the national provincial championship, yet it did not get a challenge.
Neither did it challenge in 1998, when it won the provincial title.
Although he did not want to single out players from Friday night, he felt loose forwards TJ Ioane and Gareth Evans had been particularly special on the night, and made key plays.
''They made huge plays at the breakdown ... before the game, I did not have high expectations. But going into that second half, the defensive patterns were so good and as long as Otago did not make a defensive mistake out wide, then Waikato would struggle.''
Mains said the performance on Friday night showed the hard work done 18 months ago to save the union was all worthwhile.
