ALAN ARCHIBALD admits Stuart Bannigan's red card changed the game as Partick Thistle saw their League Cup dream end in a nightmare at Parkhead last night.

The Jags crashed to a 6-0 defeat in the East End as John Guidetti bagged a hat-trick, Leigh Griffiths struck twice and Emilio Izaguirre netted a rare goal on an evening to forget for Thistle.

Already behind to a stunning Guidetti free kick after Abdul Osman was penalised for a soft looking foul on the forward, Bannigan saw red for a rash challenge on the Swede just before the break.

It was to prove the turning point as Celtic ran riot in the second half and took advantage of the Jags' lack of numbers to book a place in the semi-final draw.

Archibald said: "As a manager, I don't think he has to make the challenge. He is going nowhere. That is what has made the referee's mind up.

"He is just standing there on the touchline and he should have ushered him back into the pitch.

"I think it probably is a red nowadays. The reaction of the Celtic players made it look like that as well, I don't think that helps.

"He is disappointed and he was sitting with his head in his hands at half-time. It is one of those things, you move on.

"He was here last year and he has played against Celtic a number of times. He can't blame the excitement of playing against Celtic.

"He was having a good game until that point. I thought he was doing really well for us. It was just a rush of blood."

Having gone in at the break a goal down and a man down, Thistle couldn't have asked for a worse start to the second half as Izaguirre doubled the Hoops advantage just seconds after the restart.

It was a long night from then on in for Archibald and his players as Ronny Deila's side hit the goal trail to ease over the line and into the last four of the competition.

And boss Archibald was disappointed with how his side reacted as they shipped a series of soft goals to find themselves on the end of a Parkhead rout.

He said: "We wanted to stay as rigid as we could and as compact as we could and force them down the sides. That was the disappointment from our point of view.

"They scored another wonderful free kick but we lost silly goals down to decision-making.

"There was a bit of naivety as well I thought.

"The game totally changes and your mindset has got to change when you go a couple of goals down here."

With their League Cup dreams over for another season, Thistle must quickly pick themselves up for their return to Premiership action against Hamilton at the weekend.

The Jags were roared on by a considerable red and yellow army in the corner of Parkhead and Archibald was frustrated his side couldn't give the travelling fans more to cheer about.

He said: "The fans turned out in great numbers and that is one of the biggest disappointments from our point of view. We let a lot of guys down, myself and the team."