Krul came on immediately after Ryan Taylor’s 52nd-minute goal and saved well from an attempt by Stanislav Manolev.
Krul:“I was not expecting to be in action straight away and making such a good save.
“All of the players were wearing heart rate monitors to see how well they are progressing.
“They tell you how many runs are being made by everyone so no one can get away with hiding – except me, I am fine, I did not have to wear it!
“It was a nice result and nice for me to see a few friends. They had six or seven lads with the national team with whom I have come through.
“It is nice to win games but it is more about getting people going and as Manchester approaches we will need to pick it up more.
“Tomorrow (when Newcastle are at Deportivo La Coruña) will be the time to step up further and we are all looking at Glasgow as the one for us to really pick it up."
Last week Krul signed a new four-year contract and the Dutchman says he has “a good feeling” he can finally become the Magpies’ number one after five years learning his trade.
He added: “I always said my dream was to play in the Premier League.
“I would love to do that with Newcastle. It is going to be a great four years and hopefully it will lead to me becoming number one.
“I have to keep pushing Steve Harper. I have a feeling a good feeling even though I have a very good goalkeeper ahead of me.”
Joey Barton missed Saturday’s match with a slight groin strain but looks almost certain to start tomorrow.
Meanwhile, Bolton Wanderers manager Owen Coyle has confirmed Newcastle’s interest in defender Jlloyd Samuel, though it may not manifest itself in an offer.