In their first play-offs game since 2013, they shocked his former club with a 19-0 win that now leaves them just 80 minutes from a maiden Grand Final.
Rovers finished bottom last year but - having finished sixth - will now travel to Catalans Dragons on Thursday for a place at Old Trafford.
“I am so proud and happy for the people who support us as it’s been a long time between drinks,” said Smith, who was missing nine first-team regulars to injury.
“I’m really pleased for those fans over there and the owner, too.
“I like the attitude of my guys. Not many people have given us much hope except the people in our camp but we came out and did it.”
Rovers led 6-0 at half-time courtesy of Jordan Adbull’s try and despite seeing Albert Vete sin-binned.
They defended magnificently and then scored further tries via Mikey Lewis’ fine solo effort and Jimmy Keinhorst.
“We kept swinging and we just grew as we got further into it,” added Smith, as they vanquished their star-studded third-placed opponents.
“It felt we were able to handle anything thrown at us.
“We got tested and I’m really really proud of the last-ditch scramble defence to come up with some of the try-savers they did in and around the line.
“It was just awesome and shows how much pride they have in their tryline.
“We’ve not nilled many sides so to get it against a team with so many stars in their squad was pretty remarkable really.”
Smith, who hopes to have George Lawler and Korbin Sims back for Thursday’s showdown in Perpignan, added: “I thought we copped a few tough calls and you have to be able to ride that out.
“It happens and you have to deal with it. We did.
“Even down to 12 men just before half-time we had some opportunities to extend our lead.
“We didn’t have that energy last week. We had it today and that togetherness and when there’s a bit of adversity it pulled us together along with the fact we had injuries.
“It was a case of roll our sleeves and get on with it. We did. I’m really proud.”
Stand-off Abdull impressed at the end of a week where he was nominated for Man of Steel and in only his third game back after a broken wrist.
Smith said: “He was big. Last week he got tackled once and got the wrath of his coach.
“He spent a lot of time reviewing his game. That’s what I like about him; he goes and does something about it.
“But everyone contributed.”