Steve Banks is in the twilight of his career and playing in St Johnstone's goal only because of the absence of regular keeper Alan Mannus through injury.

As a veteran who has been in the professional game for more than quarter of a century, the Londoner - who turned 42 yesterday - still knows a trick or two about the art of shot-stopping. He is also capable of astute observation, as well he might be with the benefit of such experience to call upon.

Banks made two or three dramatic saves in St Johnstone's one-sided victory over Forfar Athletic in the fifth round of the William Hill Scottish Cup. Immediately afterwards, he turned his attentions to their next opponents, Celtic, whose goalkeeper Fraser Forster conceded twice as the Parkhead side exited the competition in defeat to Aberdeen, and in the process saw his long record of shut-outs brought to an end.

"Celtic have been in great form but would it have lasted forever?" Banks said. "Well, it hasn't lasted forever now that they've lost to Aberdeen and they will be keen to put things right against us. But we have a lot of confidence ourselves after the win at Forfar and we'll go into that game determined to get another."

Turning his attentions to his countryman, he added: "Fraser Forster has done very well in getting an England call-up and can only get better with age. At times, when Celtic maybe would have lost games, he has pulled them out of trouble with some crucial saves. So if [Roy Hodgson] decides to pick him for England's World Cup squad then I'm sure he won't let them down."

Banks pushed up the average age of the St Johntone team significantly, but he displayed agility when he was called upon to prevent Forfar from making a meaningful impression on proceedings. The hosts' Rab Douglas, also born in 1972, endured a more torrid afternoon, as a couple of his attempts to punch clear merely to presented Stevie May and Frazer Wright with opportunities to score before half time - which they took.

After having conceded four goals in the League Cup semi-final defeat to Aberdeen last week, Banks was pleased that any notion of a shock was dispelled so early.

"I'm a bit happier this week," he said. "It was nice to get a clean sheet, especially after the stick I took last week for the goal I lost [with a poor kick-out to Adam Rooney]. I got a hard time last week and was determined to do well at Forfar because of it."

Goals by Michael O'Halloran, the Scotland Under-21 international signed from Bolton Wanderers last month, and another newcomer, James Dunne, a loanee from Stevenage, left Dick Campbell, the Forfar manager, accepting his side were no match for their opponents.

"I was very impressed by St Johnstone," he said. "I didn't quite realise how good they were."