The winning margin could have been even greater and the three points hoisted them above yesterday’s opponents and into ninth place.
It was a memorable afternoon for the Jags, although it was difficult to gauge how impressive they had been given the poverty of the Ayrshire side’s performance.
“We didn’t start well,” said home manager Gary Locke. “We lost two really poor goals – goals that are easily avoidable if we do our jobs. I said to the players: ‘You can’t just turn up one week out of three. You’ve got to turn up every week because it’s a tough league.’ We didn’t do the ugly side of the game. That’s why we lost.
“As a manager it’s so frustrating, especially at home. To lose five goals in any game is an embarrassment.”
Killie may have shut out Celtic at Parkhead seven days earlier but they were breached twice inside the opening quarter of an hour here. For the opener, the home defence was caught out when their attempt to play offside misfired, leaving leading scorer Kris Doolan with the freedom of the 18-yard box. He collected Steven Lawless’s reverse pass and calmly placed the ball beyond the advancing Jamie MacDonald.
Seven minutes later Doolan was again left unmarked at a Gary Fraser free-kick and took advantage of Killie’s laxity to head home at the far post.
The home side refused to panic, however, and Josh Magennis hauled them back into it with a perfectly executed right-foot volley from Mark O’Hara’s inviting delivery.
Forced to chase the game, the hosts were wide open to counter-attacks and, when MacDonald could not hold Robbie Muirhead’s driven cross, Gary Fraser fired home the loose ball.
Worse was to come for the hosts. Muirhead, whose sale to Dundee United prompted then Killie manager Allan Johnston to resign, beat MacDonald high to his left with an Exocet of a shot from 35 yards.
Skipper Mark Connolly briefly reduced the leeway with a looping header from a Steven Smith cross.
Muirhead was not finished, however, and, collecting a pass from Lawless, he drilled the ball low inside the goalkeeper’s left-hand post for his second of the match and of his loan spell at Thistle.
Indeed, in spite of the emphatic scoreline, Thistle left bemoaning the opportunities that they spurned.
“It was great to get a two-goal start so early in the game,” said Fraser. But I think my goal was the turning point because it set us on our way.
“At 2-1 you’re never safe but we knew at half time that, if we could score the next one, then we’d win the game. I was delighted to get the goal but we’re definitely disappointed we didn’t end up with more goals.”