The Buddies were battered for their defensive set-up and they left with nothing after succumbing to goals either side of the interval by Victor Wanyama and Gary Hooper.
Ahead of Friday night's SPL clash with Motherwell in Paisley, Lennon claimed his team, sitting second bottom of the table, were judged by double standards against the champions.
He told Press Association Sport: "The team that loses a late goal with that approach deserve everything they get and we deserved everything we got last week.
"But yet, when Celtic lose 2-1 to Barcelona in the 90th minute, they are unlucky, but it was the exact same game-plan (we had) and we were in the game until the 85th minute.
"And in terms of finances, Celtic are a lot closer to Barcelona than St Mirren are to Celtic.
"I know reporters have to write something and they have decided not to concentrate on Celtic's 2-0 victory, they want to have a dig at us.
"But I will ask anyone in the media, how many times has my team played like that?
"We went there with a game plan and it worked fantastically well for us, they didn't cut us open in open play, they scored with two set plays and where we let ourselves down was when we had the ball."