The Celtic boss was gutted to see their dream of completing the league campaign unbeaten vanish 11 games from the finishing line.
But he is heartened to see his Bhoys are hurting as much as he is after losing to the Dons, having played for 78 minutes with 10 men after Virgil van Dijk was sent off.
Lennon is urging them to pick themselves up and start another winning run when they play Inverness at Parkhead on Saturday.
The run can't be as long as the one just ended - but it will take them over the line in the title race they still lead by 21 points.
Now without the clean-sheet record and the unbeaten run incentives, Lennon knows the desire to get back to winning ways will have to come from within.
But he has no fears that there will be any hangover, and said: "If we play as we did last night, not many teams will live with us.
"Aberdeen couldn't live with us in the second half, and that was with an extra man."
The introduction of James Forrest at half time, when Celtic were already 2-0 down to a wonder strike from Jonny Hayes and a poorly-defended second goal from Adam Rooney, brought the Hoops right back into the game.
Forrest scored with almost half an hour to go, but the equaliser eluded the champions.
The big disappointment for Lennon was that the youngster was not fit enough to start.
"I think he is the best player in Scotland," said Lennon.
"He has had a groin problem and has had an injection, so we couldn't really start him in this game.
"We were not sure how fit he would be. But at 2-0 down at half-time we just thought we had to get him on.
"It was earlier than we wanted to use him but he was outstanding."
Forrest was not the only player to earn praise on a night when Celtic were tested to the maximum.
"I thought Nir Biton was magnificent, and I really enjoyed watching him play," said the manager.
"Scott Brown was also excellent.
"There was great drive and intensity and quality about our play, and a lot of belief. They just were not prepared to lie down, and that was a significant step in the right direction for me."
Lennon blamed refeee Craig Thomson for the defeat thanks to the decision to dismiss van Dijk after he brought down Peter Pawlett as the Dons winger tried to burst into the box.
"I thought the referee ruined the game," he said. "It's not a sending-off. Pawlett was going across the goal rather than towards the goal. I'm pretty sure Ambrose would have got across."
The defeat could ruin more than the game, too if it means the campaign starts to peter out.
But Lennon already has plans to avoid this and is ready to change the side - Van Dijk will be suspended - to help build fresh impetus for the finishing burst.
The manager said: "I will have to look at a few things and maybe give some players opportunities.
"But I want to win the title as quickly as possible and then give some players a little bit of a break.
"I want to have a look at the squad, but I know what I have got.
"It needs a few adjustments for going forward to next season, and that is what we are now looking to do."