Celtics fans were shaking their heads leaving Boston Garden last night. How could their team, up by 28 points against a LA Clippers that traded half of its team a few days ago, could end up losing to that team 123-112?

But it happened.

And what's more, Kyrie Irving left the game with a knee strain. His status is uncertain.

The Celtics led by 21 points at halftime and then got outscored 28-12  in the third quarter. The fourth quarter was even worse - allowing the Clippers to score 42 points.

The boo birds were out at the Garden.

The Celtics couldn't play defense, eight Clippers scored in double-digits. And, the C's could generate no offense scoring 38 second half points.

The loss drops the Celtics to 35-21 with a matchup vs Philadelphia Tuesday night.