The Seagulls boss was absolutely incensed with Saints player Sean O'Connor after the player's antics inspired a brawl on the pitch at Richmond Park
The Seagulls defeated the Saints 1-0, but the game will be remembered for the melee that followed Jason Byrne's dismissal.
Speaking to extratime.ie, Devlin said that he felt the player had 'conned the referee' by play acting and faking injury.
“It was unbelievable what he (Sean O’Connor) did. The player dived onto the ground, rolled around the place and conned the referee," he said.
"I saw it straight in front of me, and there was nothing in it. It was pure gamesmanship
“I just shook hands with Liam (Buckley) after it but I’m not happy about it at all," added Devlin.
"They should have put the ball out. We did it twice in the first half when their players went down. Shane (O’Connor) had to go off so it’s clear he was injured.”
St Pat's boss Liam Buckley admitted that he would have preferred if his players had done the 'proper' thing by putting the ball out of play.
“I’m not sure what’s happened there," said the Saints' boss. "They definitely came together. It’s fairly inconclusive from the camera. I can’t see Darren Meenan doing anything either.”
He added: “In hindsight I would have preferred my players to knock the ball out and just get on with it. But that said, he’s gone down with cramp. If it was anything serious the ref would have stopped it.
"But ultimately, we would have preferred to knock it out and start it again as they did on a couple of occasions. That’s the proper way to do it”, he concluded.