The Celtics gave Amari Williams the largest workload of his young NBA career Monday night. How did he handle it?

“I thought Amari did a great job today,” Jaylen Brown said after Boston’s 102-94 win over the Portland Trail Blazers at TD Garden. “I thought he looked exceptional.”

With backup center Luka Garza sidelined with an illness, Williams logged a career-high 26 minutes in the win, outpacing starter Neemias Queta (22). The second-round rookie out of Kentucky, who’s split time between the NBA and the G League as a two-way player, held his own against Blazers big men Donovan Clingan and Robert Williams III, finishing with nine points, seven rebounds, one assist, two blocks and one steal.

“(It was) just a good matchup, one for the length that they have on their bigs, Clingan and Rob, and then his ability to screen,” Celtics head coach Joe Mazzulla said. “They just do such a good job of the ball pressure and the pickup points, and so (we wanted to) have another guy out there that can create separation for our guards. I thought he did a good job on both ends of the floor.”

Williams was especially productive in the first half, during which Boston outscored Portland by 15 points with him on the floor.

During one three-minute stretch in the first quarter, he fed a pass to fellow rookie Hugo Gonzalez for a contested layup, threw down a dunk off an assist from Derrick White, blocked a Jerami Grant shot and drew a foul on a layup over Robert Williams III, the former Celtics center. He notched another block and a steal in the second quarter, the latter sparking a fast break that produced two free throws.

Though his impact tailed off after halftime (0-for-4, two rebounds, four fouls, minus-11), Williams left a positive impression on his veteran teammates.

“He came out, he protected the rim, he was where he was supposed to be for the most part,” Brown said. “Amari made it easy for us tonight. Any given night, depending on how the team is playing us, that communication has to be great.”

“I thought he did great,” Payton Pritchard added. “His rebounding, boxing out, protecting the rim. We’ve got to use Amari more for his passing ability, because he can really pass.”

Pritchard was on the receiving end of one important Williams pass late in last Friday’s double-overtime win over Brooklyn.

Called in from the bench in overtime after Queta and Garza both fouled out, Williams assisted on a Pritchard 3-pointer that cut Boston’s deficit to two with 4.5 seconds remaining. After Gonzalez hit a last-second three to force a second OT, Williams played the rest of the way, scoring a go-ahead layup through contact and helping seal the 130-126 victory with an emphatic block.

Williams made his first NBA start the following night against Chicago. He was less effective in that game, playing just 10 minutes and looking hesitant at times in a 114-111 loss.

“Chicago’s a much faster, more free-flowing, dribble-drive type team, and (Monday) was more of a slugfest to where he can kind of impact the game on both ends of the floor,” Mazzulla said. “So I think a little bit of it is this matchup really suited him, and his strengths were kind of highlighted in his ability to set screens for us and his ability to help protect the rim and rebound. But it’s also his work ethic. Our system is constantly changing, so you have to be able to make reads on the fly on both ends of the floor. It’s a credit to him and our player development staff, but also to his teammates.”

Most of Williams’ professional playing time thus far has come with the G League Maine Celtics, who utilize the same system and terminology as their parent club. The 23-year-old has posted strong numbers in the minors, averaging 14.6 points, 11.3 rebounds and 1.7 blocks per game while shooting 60.9%.