Celtics fans shout vulgar Kyrie Irving chant after NBA Finals win over the Mavericks

Before the Celtics raise their 18th banner to the TD Garden rafters, the Boston faithful spent the hours after their historic NBA Finals win hoisting themselves atop police trucks, street signs, lamp posts, and just about anything that offered a higher vantage point.

Boston’s Game 5 blowout win over the Western Conference-champion Dallas Mavericks gave fans two reasons to celebrate: Not only did the Celtics break a tie with the 17-time champion LA Lakers for the most titles in NBA history, but Joe Mazzulla’s team also beat the hated Kyrie Irving.

‘F*** Kyrie,’ Bostonians chanted late into the evening on Monday.

A former Celtics guard who reneged on a promise to stay in Boston before defecting to Brooklyn in 2019, Irving remains friendly with his old Boston teammates and was seen giving hugs to Jayson Tatum and Jaylen Brown.

But the animosity he felt from the crowd during the game poured onto the streets after his 15-point effort in the 106-88 loss to the Celtics.

Boston Celtics fans celebrate after beating Dallas Mavericks 106-88 in Game 5 of the Finals

Kyrie Irving scored 15 points on 5 of 16 shooting before donning his 'Enlighten Warrior' hat

Nearby, a group of Celtics fans could be seen mounting a police truck as a few officers tried in vain to keep overzealous pedestrians out of harm’s way. A few Celtics fans could be seen flipping off the officers standing outside the van.

And although the song is usually reserved for Red Sox games in Boston, Celtics fans did several renditions of Neil Diamond’s ‘Sweet Caroline.’

The Celtics have scheduled a championship parade and rally for Friday morning.

Earlier Monday, Irving reportedly became upset over an 'inappropriate' remark directed at him when he crashed into the front row during the second quarter.

'Irving was upset,' said ESPN’s Mike Breen, who was seated nearby. 'Somebody said something to him, inappropriate while the guy's down on the floor, which was a disgrace. And Irving bounces back up and gets back on the floor.

The remark and the person who delivered them have not been revealed.

Boston fans hit the streets on Monday to celebrate the team's record-setting 18th NBA title 

While Celtics fans gathered outside, Jayson Tatum (right) showed off the Larry O'Brien trophy 

Police take security measures as Boston Celtics fans celebrate the team's record 18th title 

It was only three years ago that a Celtics fan was arrested and ordered to stay away from the city's TD Garden after throwing a water bottle at Irving during a playoff game.

Irving and the Nets got the best of the Celtics in 2021, but it was Boston that swept Brooklyn in the first round of the 2022 postseason as Irving was reduced to flipping off the crowd at TD Garden.

There were no such theatrics from Irving on Monday in Boston, where he lovingly discussed sharing hugs with his former teammates.

‘So when I was shaking everybody's hands, that was more of a sign of respect for their journey,’ Irving said of his former teammates while wearing a hat reading 'Enlighten Warrior.'