Frustrated Hibs boss Neil Lennon was at a loss to explain his side’s collapse against the Championship’s bottom side.
He admitted: “It was poor, we weren’t at it. It’s the first defeat in three months. The better team won but we weren’t ready.
“We gave them all the warnings beforehand that this team is going to be fighting for their lives and hungry and we’re going for a title so we should be just as hungry but there was only one team that deserved to win the game tonight and that was St Mirren.
“I hope their focus isn’t on the cup but they looked like that tonight. St Mirren had more energy more urgency, more life. I send my teams out to play that way and that’s not a reflection on me.
“Maybe it’s a good thing they lose a game in that manner as hopefully it’ll galvanise us to compete and start games better than tonight.
“I don’t know if it’s complacency or maybe some of them can’t do it. Every game from here on in is going to be like that. We have to be ready and we have to win.”
Saints boss Jack Ross praised his improving side, saying: “It is probably as well as we’ve played all season.
“We have played well at other times but given the calibre of the opposition and where they are in league, we had to be good and we were.
“I thought for the full game we were at it, we are at a good place as a squad and I think that is showing in our performances and results recently and it’s about continuing that momentum. We’ll take belief from that.
“They have good players and we spoke about that before the game but I believe we have good quality players in there as well.
“Stevie Mallan’s pass for the first goal demonstrates the quality that he’s got. For me, Stephen McGinn has been the biggest reason for our turnaround because he brings out the best in the others.
“Stelios is probably better going forward than defensively but he was good defensively tonight as well. He is very two-footed, and his two finishes were terrific. I think he enjoyed himself.
“He’s been great and he’s made a valuable contribution.”