His first save was an instinctive block with his right wrist following a flowing move from the home team, while the second was even more impressive as the Englishman pushed Thompson's drive onto his left-hand post.
Lennon said: "We're disappointed not to have won that, especially when you consider the chances we created.
"It was a big test for us playing against the second best team in Scotland at this time. But we more than matched them and at times some of our football was breathtaking.
"I'm just disappointed we didn't have a goal to show for it. Brill had three fantastic saves in the first half to keep us out.
"To look at where we have come from the opening day of the season to now is encouraging."