BOSTON — With about a third of the typical roster inactive Monday, the Boston Celtics needed someone to step up against the New Orleans Pelicans.

Jayson Tatum and Marcus Morris both rose to the occasion.

Tatum was Boston’s go-to guy out the gate, scoring nine points in the opening frame. He didn’t slow down in the second quarter, adding six more points to help increase Boston’s lead to 59-53 going into the break.

When the C’s came out of the tunnel for the second half, Morris took over as the hot hand.

The 29-year-old couldn’t miss to start the half, hitting three straight 3-pointers and going on a 9-3 run by himself to increase the Boston lead to 13.

Morris’ reign of terror on the Pelicans continued into the final quarter as he put in another 10 points to help lead the C’s to their sixth straight victory, a 113-110 win over New Orleans at TD Garden.

Although Morris took over in the second half, Tatum contributed six points of his own in the final two quarters to get his game total to 21.

Celtics head coach Brad Stevens had some high praise for Morris after the win.

“He’s a hard guy to guard. So you put a smaller guy on him, he posts you like he did at the start of the game,” Stevens said. “Put a bigger guy on him and he plays off of — against those guys in close outs and that’s tough, because he’s a really good shooter and can put it on the floor.”

Although Morris made an impact on the stat sheet from a personal level, he was quick to laud his teammates after the game.

“The biggest thing was my team did a great job continuing to find me,” Morris said, “but still it was inside the offense and it wasn’t forced. I think that was the best part.”

The Celtics will look to extend their season-high six-game winning streak Wednesday night when they take on the Washington Wizards on the road.

Here are some other notes from Monday’s Celtics-Pelicans game: 

— Celtics first-round pick Robert Williams III made a big impact with his extended minutes.

Williams received loud ovations each time he stepped on the court, and he earned it Monday. The rookie scored seven points and hauled in 11 boards, to go along with not one, but two blocks on Anthony Davis.

— Boston’s first-quarter offense remained on fire against New Orleans.

Throughout the Celtics’ six-game winning streak, their scoring in the first stanza had been immense. After outscoring the Pelicans 28-21, Boston now is plus-53 in the first 12 minutes during the winning streak.

— Jaylen Brown remained red-hot off the bench.

Since coming back from injury, Brown has thrived as a reserve scoring 21, 23 and 19 points respectively.

Thumbnail photo via Greg M. Cooper/USA TODAY Sports Images