The Perth side played most of the second half two men short after Chris Millar was ordered off, joining Steven Anderson, who was shown a red card in the first half.
But despite the numerical advantage and the bulk of the chances, the hosts had only Paul Dummett's goal to show for their efforts as the visitors' overworked defence held out for a 1-1 draw thanks to Murray Davidson's early goal.
Lennon said: "It was frustrating dropping two points.
"We started well and I was disappointed at losing the early goal, especially as we had talked about the runs made by Murray Davidson which should have been tracked by John McGinn. Apart from that, the young man (McGinn) showed great maturity and could have scored two or three goals.
"For the second week running we created so many chances, but we need to be ruthless in front of goal. I thought we made it count when we had one extra man and then two and was delighted with the number of crosses and chances we got in the box.
"Their keeper (Alan Mannus) has made some terrific saves, but while I'm delighted at the chances we are creating we need to take them."