Tommy Wright believes a more positive attitude in the second half saw his St Johnstone side run Celtic close in their
"There was more energy and belief that we could do something in the game," said Wright, whose team trailed by two goals at half-time at Celtic Park.
"People worked harder off the ball and there was drive and desire to do well.
"That's how easily it can turn in games for you. We were unfortunate at the end not to grab a point."
St Johnstone certainly improved after the break but some Celtic fans had already drifted to the exits by the time Liam Caddis's 81st-minute goal had halved the deficit created by Teemu Pukki's and Charlie Mulgrew's first-half goals.
And in the final minute Stevie May's header struck a Celtic post and home keeper Fraser Forster saved a Dave Mackay shot to make sure Celtic kept all three points in a match they had looked like dominating from the off.
Manager Wright said of Saints' first-half display: "We sat too deep and we didn't get close to them. I don't think we worked hard enough on or off the ball.
"When we did win the ball there weren't enough options. People weren't brave enough to make an option for the person on the ball and that caused us a few problems in the first half.
"I think we were unlucky with the two goals. I think they were two deflections.
"We asked for a reaction in the second half and we got it.
"We controlled parts of it and we are a bit unlucky not to get a goal at the end when we hit the post and unlucky not to get a penalty as well."
His striker Steven MacLean was angry when referee Alan Muir waved away his appeal for a spot kick after he had been challenged in the box by Anthony Stokes.
"Steve said there was contact. There was no reason for him to go down," Wright argued.
"That was maybe the wee rub of the green that you need to get a draw but the referee saw it different so we just have to accept that.
"The second half performance was a bit more like us.
"We showed Celtic too much respect in the first half. I think it was 20 minutes before we made a tackle. Celtic were in total control of the game but Alan Mannus didn't have a lot of saves to make."