The NBA's Christmas Day slate began with a slow-paced, but high-scoring battle between the Boston Celtics and New York Knicks. The Celtics held off a late, furious Knicks run to escape Madison Square Garden with a 119-114 victory. This was Boston's fifth win in six games and New York's fourth loss in six games.

Takeaways:

Tough guards come up big

Boston had led the entire second half until New York went on a 16-3 run in 3:34 to tie the game late in the fourth quarter. To break the tie, Al Horford found Marcus Smart wide open for a 3-pointer, and the defense-first guard made the clutch jumper. On the next trip down the floor, Avery Bradley stole the ball from Carmelo Anthony on the perimeter, essentially putting the game away. (Horford blocked Kristaps Porzingis a couple of possessions later to really end it.)

Smart had a busy night, spending time guarding the taller Anthony and the 7-foot-3 Porzingis -- in the fourth quarter, he perfectly boxed out Porzingis, but didn't get a call when Porzingis jumped over his back. This was all after getting bloodied up by a Derrick Rose elbow when playing transition defense. He finished with 15 points on 5-for-9 shooting, plus seven assists and two rebounds.

This wasn't one of Bradley's best statistical nights -- he had 11 points on 12 shots with six rebounds, two assists and three steals -- but he did all the things that Celtics fans love him for: switching onto bigger players, moving the ball, spacing the floor and coming up big when needed.

Trust the process

New York built an early lead largely because Boston missed 13 of its first 16 attempts from beyond the arc. Even when the Knicks appeared to have all the momentum, though, the Celtics had little trouble getting open looks. After that awful start, Boston made six of its next seven 3-pointers, and it finished 14-for-36 (38.9 percent) from deep.

When the Celtics are at their best, they play the same way regardless of whether or not the shots are falling. This is what allowed them to take the lead in the first place and hold onto it when New York went on that late run.

The Knicks worked extremely hard throughout, and that's not entirely meant as a compliment. Their 28-22 lead at the end of the first quarter was mostly the result of making contested midrange jumpers, and, all afternoon, it relied heavily on tough shot-making or Derrick Rose's drives to the hoop to generate offense. This was almost enough to steal the game, but it never seemed like its success was sustainable.

Al Horford dunk
Al Horford puts Kristaps Porzingis on a poster. USATSI

Weird Christmas for Melo

Anthony had a good-not-great line: a game-high 29 points on 9-for-24 shooting, plus seven rebounds, two assists, a steal and a block. For much of the night, though, he struggled. Anthony shot 1-for-7 in the first half, halting the Knicks' offense and forcing bad shots over Jae Crowder (and, sometimes, help defenders).

He overcame his slow start to score 15 points in the third quarter, but it never seemed like he was really giving the Celtics problems by trying to score in isolation. The best thing he did was make all nine of his free-throw attempts, and the worst thing was that turnover in crunch time.

Which dunk was better?

Late in the second half, Porzingis threw down a two-handed hammer, to the delight of the MSG crowd. He had a totally open lane because both Amir Johnson and Horford sprinted to the corner and Smart knew better than to jump once the Unicorn was headed his way:

As cool as that was, though, it might not have been the best throwdown of the game. In the third quarter, Porzingis found himself on the other end of a straight-down-the-middle drive and dunk. Look at where Horford takes off from and the extension he gets:

Personally, I'm going with Horford. That's a beautiful play.

Isaiah keeps his streak going

With 27 points on 9-for-23 shooting, Isaiah Thomas reached the 20-point mark for the 15th straight game. According to ESPN Stats and Information, he is tied with Chicago Bulls star Jimmy Butler for the longest such streak in the league.

Thomas put pressure on the Knicks' 25th-ranked defense all game, getting into the paint with ease and finishing in traffic. Uncharacteristically, he shot just 2-for-8 in the fourth quarter ... but he still managed to score nine points in the final frame, in line with his season average. Only the Oklahoma City Thunder's Russell Westbrook scores more than Thomas in the fourth.

Boston's flaws are still visible

The Celtics outplayed the Knicks in almost every statistical category, but this one was close because of two issues that they've had all year. New York grabbed 40 percent of the offensive rebounds available, and it went 24-for-27 from the stripe. Boston has had trouble keeping teams off the glass and off the free-throw line this year, and its pretty offense and strong individual defenders don't always make up for that.