On a day when the heavens opened at Rugby Park, the proverbial floodgates did likewise, as a deluge of goals from Partick Thistle overwhelmed the porous Kilmarnock defence.

The impressive visitors eventually won out by three clear goals, but in truth, the margin of victory might have been even greater as they continually breached the calamitous home rear-guard.

An early double from Kris Doolan looked to have Thistle on easy street, but Josh Magennis hit back for the home side to drag them back into the game midway through the first half.

Gary Fraser restored the visitors’ two-goal cushion shortly after the re-start though, and the game looked wrapped up just after the hour as Robbie Muirhead produced an absolute thunderbolt into the top corner.

Mark Connolly headed a goal back for Kilmarnock with just over 15 minutes remaining, but Muirhead got his second of the day almost immediately to eliminate any remaining doubts about the destination of the points.

Kilmarnock manager Gary Locke praised his defence last week after earning a clean sheet at Celtic Park, but he couldn’t hide his anger after watching a polar opposite performance from his lacklustre outfit.

He said: “It was embarrassing at times to be fair and the players know that. It was the same team who did well at Parkhead last week barring one change with (Greg) Kiltie in for (Rory) McKenzie. They got plaudits last week but they will get stick this week and rightly so.

“We didn't start well. We lost two really poor goals – goals that are easily avoidable if we do our jobs. I said that 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 today and that's why we got beat.

“As a manager it's so frustrating, especially at home. To lose five goals in any game is an embarrassment. The goals we lost were terrible goals apart from Robbie’s strike from 35 yards out. You hold your hands up and say it's a fantastic goal but every other goal, if we defend properly, we don't lose those goals.

“It's certainly a bad day at the office for us. We are not going to get away with losing goals like that every week. We can't keep conceding goals the way we conceded them today. Recently, we have done well and got plaudits and defended well, like last week when we defended brilliantly. But you can't just do it for one game, you have to do it consistently.

“As good as we were last week, it was the other side of the coin today.”

As far as first goals for your club go, the Muirhead strike for Partick Thistle that Locke mentions wasn’t a bad one. The on-loan attacker produced a moment of outstanding quality as he got his head up and unleashed a rocket of a shot into the top corner from distance, leaving Jamie MacDonald in the home goal grasping at air.

“He does that every day in training,” said Partick Thistle manager Alan Archibald.

“Robbie’s always got that. It’s just about finding his best position. I think one day he’ll grow into becoming a striker.

“I’m delighted for Robbie. We brought him in after last week and I was a wee bit worried because you don’t always want to change a winning team, but we thought he would give us something today against his former club.

“He settled into the game slowly, but I thought he was fantastic in the second-half, the goal gave him a real lift and he was great after that.”

The downside to Muirhead standing out so spectacularly for Partick Thistle is that parent-club, bottom-of-the-table Dundee United, will almost certainly recall him at the earliest opportunity.

“I think they’ll take him back now!” Archibald laughed.

“We done the deal when Jackie McNamara was there, so I think he’ll be back at the start of January.”

The emphatic win keeps up the Firhill side’s recent impressive run of form, and puts them above Kilmarnock into ninth place in the Premiership standings.

Archibald said: “We had a good start to the game and settled really well. We got two great goals and we were delighted, but credit to Kilmarnock, they came back at us and got a goal back during our worst spell.

“We looked a bit rattled for 10 minutes and half-time came at a good time for us.

“I think in the end though when Kilmarnock started chasing the game it really suited us, and there was some fantastic play from all of our front guys.

“It’s been coming because we’ve played like that before and not had any credit for it, so it’s great to come away with a win this time.”