Rowan Vine's first goal for St Johnstone gave the home side a shock 2-1 Clydesdale Bank Premier League win over Celtic at McDiarmid Park.
Kris Commons drove the champions into the lead in the third minute but Saints striker Gregory Tade levelled in the 18th minute before the visitors were denied what looked a clear penalty when Steven Anderson challenged Commons inside the box.
But Celtic were well off the pace all afternoon and in the 80th minute they paid dearly when former QPR striker Vine curled the ball in from the edge of the penalty area to hand the Perth club their first win of the league campaign.
It looked like it was going to be a stroll in the sunshine when Hooper set up Commons 20 yards from goal and watched as the Scotland midfielder drilled a shot low past Alan Mannus and into the far corner of the net.
But Saints got back into the game and after Charlie Mulgrew was penalised 25 yards from goal for going through the back of Tade, Celtic goalkeeper Fraser Forster had to dive high to his right to prevent Dave Mackay's free-kick dipping in under the bar.
Hooper and Victor Wanyama had shots which flew wide of the target, but in the 15th minute Celtic defender Kelvin Wilson had to throw himself to block a goal-bound shot from Peter Pawlett. The Saints wide-man had cleverly worked a one-two with Murray Davidson before driving into the visitors' box.
Three minutes later Wilson was less vigilant, as was Mulgrew, when Vine played the ball into Tade, who turned and drove low past Forster from the edge of the box.
There was controversy in the 26th minute when Anderson, chasing his own header to Mannus which was short, tackled Commons inside the box without getting the ball but referee Euan Norris turned a deaf ear to a vociferous and valid penalty claim.
Lennon refreshed his side in the 58th minute by bringing on teenage striker Tony Watt for Miku but seconds later it was Commons who went close to restoring Celtic's lead with a powerful 30-yard drive which just cleared the bar.
Nigel Hasselbaink replaced Pawlett in the 77th minute and it paid off when Hasselbaink played the ball to Vine who neatly stepped away from Thomas Rogne before curling a wonderful shot past Forster and into the far corner.