It wouldn't be long before the hosts had their second, with the striker again finding himself in the right place to double the lead.

Kyle Vassell's finish gave the visitors hope, as did a red card for Dara Costelloe after a VAR review.

But neither of those could prevent interim boss Alex Cleland moving St Johnstone to within three points of Livingston and Ross County.

Given what has come before this season, not even the most optimistic of St Johnstone supporters could have predicted such a sensational start.

Some were still settling into their seats when Clark had followed up on Chris Kane's rifled strike to put the hosts in front within the first minute. The flag was up, but VAR made sure the home fans could celebrate a rare lead.

Fast out the traps, St Johnstone's sprint continued with their veteran striker leading the way again. A brilliant ball from Graham Carey steered home expertly by Clark as Kilmarnock lagged far behind.

Matty Kennedy's long drive was a rare spark for the shell-shocked visitors, forcing Dimitar Mitov into a strong save.

Meanwhile, the newfound confidence of previously beleaguered bunch suddenly came to the fore.

Defender Liam Gordon slapped the crossbar for 30 yards. Kane did some keepy-uppies in the box before trying an overhead kick. Was this the real St Johnstone?

On course for the first win of the season, their nerve would be tested when Kilmarnock struck early in the second half.

Vassell's fourth goal in three games, crafted by a wonderful cross from Kennedy, gave the visitors a lift, though Mitov should have done better than letting the ball slip through his fingers.

Kilmarnock's route back into the game became even clearer when Costelloe was shown red for a flying challenge on Danny Armstrong, but the Irishman's side held on for a much-needed boost in Perth.

Player of the match - Nicky Clark (St Johnstone)

You could have awarded this just seven minutes into the game. Clark's veteran instincts and leadership will be crucial if St Johnstone are to turn the tide.

Saints show resolve as Killie's away woes worsen - analysis

On Saturday, St Johnstone crumbled, capitulated and collapsed in such a manner that club legend MacLean's tenure in charge came to an end.

Home fans couldn't have asked for a better response than their lightning quick double to lift the malaise at McDiarmid Park.

All season, they've looked like a team in tatters. Rudderless up top, clueless at the back. Here, while far from perfect, they made a step towards showing the kind of fight and resolve that supporters have come to expect.

They so easily could have imploded after Costelloe was sent off, but they mucked in to seal a vital first win.

While a new beginning for St Johnstone, it was the same old story for Kilmarnock as their woes on the road continued.

Since their return to the Premiership last summer, they've won just twice in 23 away games. Against a side without both a manager and win, it's fair for the travelling faithful to demand more.

Every time they look like they could mix it up in the top six, a deflating defeat is just around the corner. If McInnes is serious about his European ambitions, their stop-start status needs to stop, and soon.

What they said

St Johnstone interim manager Alex Cleland: "The effort the boys put in was great. We're delighted, but it's one game. We've got to remember that.

"Any win gives you confidence. This is such a hard league to pick up points, as we've seen in the game we had. It was important to get the fans back on side with a good performance.

"The process, we'll leave that for the board upstairs. I said it before Callum [Davidson] was appointed, the board have appointed good managers in my time here. I won't be involved in it [the process], but I'll leave that to those upstairs."

Kilmarnock manager Derek McInnes: "We've had a lot of praise as of late, especially for the defensive part, our aggression, our competitiveness. We weren't competitive enough.

"It was such an unusual start from us. The only positive when you concede early goals is you have plenty time to score and work a way into game.

"The performance wasn't too bad overall, but the start was awful. We've got to recognise what we are as a team. We can't start any game like that. Once that ball rolls you've got to be that competitive animal."

What's next?

Both sides' next game is a home fixture with Motherwell, as Kilmarnock welcome Stuart Kettlewell's side on Saturday (15:00), while St Johnstone host them on Tuesday.