Berbatov (right) gave United the lead against Celtic in Canada
Celtic manager Neil Lennon saw signs of promise from Friday's 3-1 defeat by Manchester United, despite it being their second pre-season loss in a row.
It followed Wednesday's 1-0 defeat by Philadelphia Union on the first leg of their North American tour.
"I thought the level of performance was excellent," said Lennon. "There were a number of positives to take out of it.
"There was a lot of good football played out there and the players enjoyed the atmosphere and experience."
Dimitar Berbatov had given United a 30th-minute lead in Toronto and, although Georgios Samaras equalised from the penalty spot after an hour, late goals from Danny Welbeck and Tom Cleverley gave the English side victory in the friendly.
There is not a lot in it between the two teams because the Scotland-England thing motivates both sets of players
Manchester United manager Sir Alex Ferguson
"The second goal came probably after our best spell in the game," said Lennon, whose side next face Seattle Sounders on Sunday.
"I was really pleased with the response of the players, particularly in the second half. Samaras made a difference when he came on."
Lennon had named a much-changed team from the side that lost to Philadelphia, with 18-year-old winger James Forrest given another chance for the senior team, while forward Shaun Maloney and defender Thomas Rogne returned from long-term injuries.
Celtic's new signing from Cardiff City, Joe Ledley, started in midfield, while South Korea international Cha Du-Ri, signed after he left Freiburg, came on as a substitute.
United manager Sir Alex Ferguson praised his Scottish opponents.
"Celtic were very competitive," he said. "That's been the way when we have played them.
"There is not a lot in it between the two teams because the Scotland-England thing motivates both sets of players."
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.