Inverness boss Terry Butcher said their 1-0 victory at champions Celtic was "mind-blowing."
It was the first time they have ever won a league game at Parkhead, and they have now done the double over the Old Firm having beaten Rangers in the Scottish Communities League Cup win at Ibrox last month.
Butcher, whose team were hammered 5-1 at home to Motherwell last week, said: "To win as a manager for the first time and to beat both Glasgow clubs in the same season on their own patches and keep clean sheets, is fantastic.
"We have created history all the time and we intend to keep on doing that. We got rid of last week very quickly, they are a great bunch of lads."
Billy McKay, who scored the only goal of the game, said: "It was great for me to get the winner. Barca came here and they are probably the best team in the world and didn't get a result but we stuck to our task and got the win.
"I hit the bar and then it got cleared off the line after that. We have lost a few late goals so it was great to hang on and grind it out.
"We had a plan to frustrate them, keep our shape and it worked."