The Celtics (13-17) nearly coughed up a 19-point lead that they held going into the fourth quarter Saturday afternoon at TD Garden, but Brandon Bass' blocked shot of Dion Waiters in the final seconds allowed Boston to earn a 103-100 victory.
Jordan Crawford and Jeff Green led the way for the C's, each posting 19 points.
Cleveland (10-19) had cut the Celtics' lead to two with under a minute to play but Bass cut off Waiters in the lane to come up with the winning defensive play.
What they'll be saying: The Celtics aren't supposed to be inching closer toward the .500 mark as the calendar readies to flip to 2014. In that sense, everything's gravy. But Boston has had its issues sustaining large leads this season. It's something to watch for if the C's get serious with any type of playoff push.
Boston hosts its final game of 2013 on New Year's Eve day at 1 p.m. at TD Garden against the 16-13 Hawks, by record, the third best team in the train wreck that is the Eastern Conference.