Rangers have struggled to overcome First Division opposition recently and manager Walter Smith admits he was far from surprised Wednesday's Co-operative Insurance Cup clash with Partick proved another tricky tie.
Rangers eventually booked their place in the draw for the last eight, but only after being pushed all the way as Kris Boyd's opener was cancelled out by Stephen McKeown before Pedro Mendes claimed the decisive goal in extra-time.
"Of course they raise their game," said Smith of lower league opposition. "That's what happens, and that's what you are always up against. I thought they played to a decent level in the second half and I thought it was a good cup tie overall."
He added: "If you look at the results in the League Cup, they are always difficult matches for SPL sides to come away from home and get a result in.
"It looked as though it was going to go to penalties and thankfully it didn't. We got a couple of tough games from Partick last season so we knew it was going to be like that.
"When you make the number of opportunities we did in the first half and only score one goal, you know you are going to have a bit of a problem.
"We are delighted to get through and Partick Thistle deserve a great deal of credit for making it a really good cup tie."
Both strikes from Rangers could be contenders for goal of the season and Smith was keen to single out Mendes for praise for his endeavour on the night.
"It was a great goal at the end," he said. "I thought we played well in the first 45 minutes and he was an integral part of that."
Kenny Miller was notable by his absence at Firhill and Smith confirmed: "He had a slight calf strain but he will be okay for the weekend."
Copyright (c) PA Sport 2008, All Rights Reserved.