Turin: After listening to taunts from the Juventus crowd for 90 minutes, Jose Mourinho couldn't help but pay them back in kind.

Mourinho had to be escorted off the pitch on Wednesday after celebrating Manchester United's 2-1 comeback win over the Italian side in the Champions League by cupping his hand to his ear to the crowd after the final whistle.

The gesture sparked a small altercation with Juventus players that overshadowed one of the most important results of the season for United, which has struggled domestically but now has a great chance of reaching the knockout stage in Europe.

"I came here to do my job and I was insulted for 90 minutes," Mourinho said. "I wouldn't do that gesture again but I don't think I offended anyone and at the time it seemed like the appropriate response to those who had insulted all my family, apart from my Inter one too."

Mourinho is unpopular among Juventus fans after managing bitter rival Inter Milan for three years.

After United's 1-0 loss to Juventus at home two weeks ago, he responded to the goading of the Italian fans by holding up three fingers toward them, denoting the treble of titles — Champions League, Serie A and Italian Cup — he won with Inter in the 2009-10 season.

This time he had another win to celebrate, after watching his team fight back from Cristiano Ronaldo's spectacular opening goal.

Juan Mata levelled with a free kick four minutes from time and Alex Sandro netted an own goal in the final minute as United blew their Champions League group wide open.

Juventus defender Leonardo Bonucci angrily approached Mourinho as he cupped his ear at the Bianconeri fans and the United coach was escorted off the pitch by a UEFA official and some members of his staff.

It was Juventus' first defeat in any competition this season.

"When I work for a club like Manchester United I need to forget my past as in those 90 minutes I represent Manchester United," Mourinho said. "But the others (Juventus fans) didn't forget.”

"And it is a great joy for me because we won against a super team, and not because they are the enemy of Inter."

Juventus, which was the only team in the Champions League still with a perfect record, remained top of Group H but is only two points ahead of United. Valencia, which earlier beat Young Boys 3-1, is two points further back.

"We shouldn't have given away those free kicks, we're giving away a lot of those at the moment, it was the only way United was going to score," Juventus coach Massimiliano Allegri said. "But the team did well, we are still at the top of the group and we have two matches which will allow us to finish first. It's OK to lose against United, but seeing how the match went it leaves us with a bit of a bitter taste."

Allegri was asked if he would have reacted similarly to Mourinho.

"No, I leave the pitch immediately to avoid reacting," he said. "I only get angry, rightly, with my team when they go to sleep every now and then."

United played better than it did when the two sides met in Manchester but Juventus had a number of opportunities and had already hit the woodwork twice before Ronaldo struck in the 65th minute.

Bonucci floated a ball over the top of the defense and Ronaldo watched it over his shoulder before volleying into the top right corner.

The Portuguese superstar immediately ran to the corner flag, lifted up his shirt and pointed at his impressive stomach muscles.

Ronaldo is the all-time record scorer in the Champions League with 121 goals, but this was his first in the competition for Juventus — although he missed one match through suspension after his red card against Valencia.

Allegri raised his eyebrows and gave a smile of appreciation at the goal.

Juventus seemed certain to be heading for all three points, with United struggling to carve out clear-cut scoring opportunities, but Mata hit a free kick into the top left corner in the 86th minute and that seemed to inspire Jose Mourinho's side.

Minutes later, Marouane Fellaini flicked on a free kick and the ball ricocheted around near the far post before going in off Juventus defender Alex Sandro.

(With inputs from agencies)