Killie had the better of the chances in a fairly quiet affair but could not get the breakthrough and had to settle for a 0-0 draw in the Scottish Premiership on Sunday.
And Johnston said: "I thought we created enough chances to win the game. We restricted them to very few chances, which was good.
"We were a lot more compact this week compared to last week, so there was a big improvement."
Killie felt they should have had a penalty when a William Gros shot appeared to strike the hand of Frazer Wright.
Johnston added: "From my position, it looked as though it was a clear handball.
"His arm was outstretched and I think that's an unnatural position, you're not allowed to do that.
"As far as I know, it looked a penalty, but it's a hard decision for a referee in a split second.
"That's where you are maybe looking for your linesman to help you out. You need to make sure you get decisions like that right."
New signings on the way
The Ayrshire side confirmed the signing of full-back Sean Clohessy on a two-year deal ahead of the game but could not register the signing in time for him to feature.
"We missed the deadline by a minute seemingly, so he wasn't available for today," said Johnston. "But it will give us good competition for places.
"Young Mark O'Hara did extremely well at right back today, so he is going to play a big part for us this season as well.
"Hopefully this week we will be bringing in at least another two or three players, who will hopefully strengthen us again. That's the plan anyway."
Saints boss Tommy Wright was very pleased with a share of the spoils following Thursday night's disappointing penalties loss to FC Minsk.
"I'm delighted with the point," he said. "It was an excellent point for us, particularly after the emotion of Thursday night and the physical exertions, even though we did freshen it up a little bit.
"I'm really pleased and I thought we showed a lot of character.
"Allan probably thinks they deserved all three points but, with the effort we put in, I thought we deserved to take a point from the game."