There was a lot of talk about Jekyll & Hyde after this encounter at McDiarmid Park but there was also the Strange Case of Paul Paton to blether about.

While Paul Hartley, the Dundee manager, was bemoaning his team’s dual personality after a timorous surrender in Perth, a goal from the aforementioned Paton was almost as startling as witnessing Doctor Jekyll undergoing his bamboozling transformation.

“It’s not like me to make that sort of run into the box and I had a bit of a nosebleed,” said the 29-year-old with a wry smile after opening his St Johnstone account with a surging advance and header which paved the way for a thoroughly dominant display by the hosts.

It was Paton’s first goal since getting on the scoresheet for former club Dundee United in February 2016 and it gave St Johnstone a much needed lift following some struggles in their own backyard of late.

After a grim and ultimately futile fight against relegation with his old club in the last campaign, Paton is enjoying a new lease of life in the upper echelons this time as St Johnstone aim for fourth place in the Ladbrokes Premiership.

“I made a big decision to come here in the summer and I think everyone knows I had a contract there (at Dundee United) and I took a big wage cut to come here,” added Paton. “That shows I wanted to come here and play in the SPL. This was for the fans. We said that before the game. It has been a bit grim here in some recent games. We have faltered. It was good we showed up.”

It was Dundee who finally condemned their city rivals and Paton to the drop last year so you could have forgiven Paton had he milked his goal and gave the visiting supporters something of a Harvey Smith salute. He didn’t, of course. “Their fans were giving Danny Swanson (another ex-United man) more stick than me so I’m happy for him to take it and for me to go unnoticed,” he said.

Paton’s header, which was added to on 20 minutes when Blair Alston unleashed a searing strike from distance, capped a good few days for him. “I got a call-up for the Northern Ireland squad to play Norway earlier in the week,” said the Paisley-born midfielder who has four caps for the country where his father was born. “I was out for a long time last season with a knee injury and I am proud of myself to be back at a level where I can be in squads. It takes a long time to do your rehab.”

Dundee will need to rehabilitate themselves after this downbeat display. With games coming up against Celtic and Aberdeen, Hartley’s troops need to rally themselves quickly as their top-six ambitions suffered a serious dent.

That Jekyll & Hyde nature is proving to be a major head-scratcher and Darren O’Dea, the Dens Park club’s captain, clearly doesn’t like what he sees at times. Dundee were out thought and out fought in every area on Saturday and gave almost 1500 travelling fans plenty of ammunition for a justifiable grumble.

“We go from the high of beating Rangers and then Motherwell to this,” he said. “We’re a strange team at times. It’s the worst thing for a manager, not knowing what you’re going to get. It’s not good enough. Anyone who was surprised that we’d get a tough game here needs a reality check. It’s always tough here. We were off it and we got punished. I was looking at the programme notes before the game and St Johnstone have five or six who have played 200 games here. That tells its own story. We have a young team, that’s why it can be a bit up and down. It’s a good crop but we have to learn quickly and this was a harsh lesson.”

With matches coming up against the top two in the league, Dundee, who have slipped to eighth, have every reason to be jittery as the split looms. O’Dea is looking for a reaction in the coming weeks.

“In a strange way it might be easier playing against two good footballing teams in Celtic and Aberdeen,” he said. “We have to pick ourselves up quickly, we can’t feel sorry for ourselves. Sometimes you come off a pitch and accept that you were beaten. We may have been outplayed but we were out fought and that is hard to take. As long as you give everything and compete to the best of your ability then you accept it. But we lost because we weren’t ready for the fight and they were.”