Hull FC, who Saints play on Friday night, took out the Cup decider against Wembley.
Cunningham believes the Black and Whites did it the hard way.
“Hull definitely did it the tough way and I’m pleased for that Hull team I really am, I’m pleased for the coach,” he said.
“He did it tough last year, he did it tough at the start of this year and he’s kicked on and found something that really works and I’, pleased for him he deserved it more than anybody.
“The biggest smile for me was for Lee Radford because I know how hard coaches work and how tireless he’s worked behind the scenes and making big decisions and working those long hours for nothing with no thanks but criticism.
“To come through the other side of that with a trophy is a good call for him.”
Cunningham is expecting a difficult encounter.
“I think in both of them games, the league games we lose by a kick of the ball on the final hooter from Sneyd 50 metres out to win by one point,” he said.
“Wnd we went over to there place, we lost Walshy in the first two or three minutes and we played with Wilko and young Theo in the halves and we should have won that game and we had chances to win both those games.
“They were both close encounters and I don’t think it’s ever a good time to play anybody.
“Hull have set ambitions on winning all three and they’ve come out and said that already, we’ve got our ambitions theyve got theirs.