The Airlie Birds were vanquished 45-0 at Magic Weekend following a wretched performance.
Former Batley Bulldogs prop Walmsley delivered a stunning performance, forcing his way over for two tries and giving his biggest hint yet to England head coach Wayne Bennett.
Hull wore Hulk-style jerseys for the event in Newcastle and Radford bemoaned: “Three of their tries are one-up carries off the dummy-half.
“We made Alex Walmsley look like a superhero today. He should have had one of the Marvel shirts on. For our big fellas that was an example of how you carry the ball and get over the advantage line.
“We were playing to go top of the table today for maybe a short period. That was a good reason to turn up and perform but we didn’t.
“It was really set for set to start with but we threw jabs and they threw bombs and I think that’s the best way I can describe it.
“When you keep taking bombs ultimately you’re going to hit the canvas at some point and that’s what happened to us.
“We’ve got to try and find out why we have been losing games like this.”
It was a perfect start for St Helens’ new head coach Justin Holbrook, the Australian who only arrived on Thursday and saw his team respond brilliantly after a 53-10 Challenge Cup exit at Castleford.
Meanwhile, he admitted Saints could be in the market to sign Australian full-back Ben Barba.
The former Cronulla star back is a free agent after being released by French rugby union club Toulon and was spotted with Saints officials at Magic Weekend.
Barba was given a 12-week ban and released by Cronulla after testing positive for cocaine in November, not long after helping the Sharks to a 14-12 win over Melbourne in the 2016 NRL Grand Final.
He sidestepped that suspension with his switch of codes but would have to complete it in Super League.