Substitute Kean's counter-attacking sucker punch inflicted St Johnstone's first home defeat for eight months and left them just four points ahead of second-placed Partick Thistle.
Saints mounted a grandstand finish to level after two earlier stri
kes from the division's top scorer Stephen Dobbie, who took his tally to 20 for the campaign. But they were caught out on the counter-attack in stoppage time and now Derek McInnes has to rally his players for a Tayside derby at Dens Park.
McInnes admitted his team had defended naively but maintained: "Saturday was always going to be a massive game for the club and I can't wait for it.
"There is pressure on us but it has been there all season. Getting back to 2-2 we were looking for a winner. We weren't gung-ho but we were punished for poor decision-making."
McInnes was infuriated by a controversial decision by referee Charlie Richmond to disallow a first-half goal, when keeper Lee Robinson flapped a cross into his own net.
"I have watched the tape with the SFL observer and it was a poor decision. It was a major one and he got it wrong," McInnes said, but added: "Sometimes you just have to take your medicine and regroup."
Dumfries manager Gordon Chisholm was relieved to stretch the gap on Airdrie and Clyde. He said: "They are going to give me a heart attack! But it was a great game for the (BBC Alba] cameras and it was vital we got a victory. Stephen Dobbie is the only player in the division that can produce that sort of quality."
Dobbie, who was moved out of McDiarmid by previous manager Owen Coyle, punished his old club in the 11th minute.
A candidate for First Division player of the year, his close control got the better of defensive duo Kevin Rutkiewicz and Graham Gartland and he rammed an angled shot under keeper Alan Main.
But Queens relied on an error of judgment from referee Richmond to preserve their advantage in the 15th minute. On-loan Rangers keeper Robinson appeared to spill a Liam Craig corner into his own net but the official indicated handball against Graham Gartland and ruled out the own goal.
At the other end, Alan Main inexplicably scooped up a back pass, but this time Dobbie wasted the shooting chance from 17 yards. Saints fashioned a clear-cut chance in the 27th minute but Martin Hardie's flashing header was aimed straight at Robinson and before half-time the midfielder was cautioned for a foul on Craig Reid.
At half-time, Kevin Moon replaced Gartland and within minutes the youngster squandered back-to-back opportunities, scooping the second over the bar from ten yards.
But after seeing his side hemmed in for nine minutes after the restart, danger man Dobbie charged down a slack defensive clearance from Steven Anderson and left the errant defender floundering by cutting inside to plant a decisive shot inside the upright from 12 yards.
With seven minutes remaining, Derek Homes surprised flat-footed keeper Robinson with a 15-yard header and then Chris Millar's drive clipped luckless Jim Thomson to find the net two minutes from time.
But the drama wasn't over and Kean's late strike deflated Perth fans prematurely celebrating a precious point.
The full article contains 588 words and appears in The Scotsman newspaper.
