Experience and effort were the key elements of St Johnstone's first win at Celtic Park in more than a decade, according to manager Derek McInnes.
Dave MacKay's 60th-minute strike settled the Scottish Premier League match in the Perth side's favour.
"We had experience in all areas of the pitch and that is important coming to places like this," said McInnes.
"We tried to be positive with two strikers and we got our reward. We worked very hard for it."
St Johnstone goalkeeper Peter Enckelman saved a second-minute penalty from Kris Commons and that was a fillip to a team that last won at Celtic Park in 1999, when Nick Dasovic was the Saints hero.
McInnes was unhappy at referee Brian Winter's decision to award the spot-kick but full of praise for Enckelman.
"I thought he gave [Anthony] Stokes the chance to put the ball in the net and Stokes put it 25 yards past the post," he told BBC Scotland.
"To then pull it back for the penalty kick was very harsh.
"To get a result like this you normally have to have your keeper playing very well.
"Peter made a very good save at the penalty kick and he had one or two after that and he inspired the team at key moments.
"We are grateful that we got away with that one."
MacKay's goal was St Johnstone's first in the SPL this season and, while it triggered celebrations among the band of visiting fans, it also led to an assault by Celtic for the remaining half hour.
"I thought the players defended with a real discipline, resolve and intelligence and a real desire to win the game," said McInnes.
"It's probably as comfortable I have been as a manager and possibly a player coming to Parkhead, but you know with their quality that you can never switch off.
"At no time did we do that.
"We had a way of playing today that we wanted to keep them going round us.
"Everybody worked extremely hard and I think it was a result that, over the piece, we earned."
According to the St Johnstone manager, the result makes up for the pain of the 1-0 home defeat by Dunfermline a week ago.
He said: "It was a disappointing result last week. We have clawed back three points we lost last week and so we are pleased.
"It's great because it's two fingers up to a lot of people who have started to doubt us this year - people questioned us losing to Dunfernline lasty week.
"But I have total belief in this squad of players. We have the right types and that will serve us well."