The Celtics (11-9) entered Sunday’s game in Cleveland (12-9) with a depleted roster and every excuse to bow out quietly.

Instead, they delivered one of their grittiest performances of the season.

Payton Pritchard had a career night, and Jaylen Brown contributed a do-everything effort as Boston escaped with a 117-115 victory. The win came the hard way, with two starters missing and a chaotic fourth quarter nearly erasing a commanding lead.

Without Derrick White (calf) and Neemias Queta (ankle), the Celtics arrived in Cleveland, patching together a rotation against a Cavs team that was also missing key pieces. Even so, Boston controlled much of the night behind Pritchard’s relentless scoring.

The guard caught fire almost immediately, pacing the offense early and ultimately torching Cleveland for a season-best 42 points on an ultra-efficient 15 of 22 shooting clip, including 6 of 11 from deep.

Brown’s shot faltered - he finished 3 of 13 from the field - but the rest of his game soared. He grabbed a season-high 12 rebounds, dished 11 assists, and recorded his fourth career triple-double while keeping Boston’s offense humming.

Boston built a 21-point second-half lead and seemed in control. But nothing came easy.

The Cavs rallied with a desperate 16-7 run to end regulation and put late pressure on the Celtics. Evan Mobley’s potential buzzer-beater missed, allowing Boston to exhale and secure its gutsiest road win of the year.

Jordan Walsh provided key support, turning in his most complete game with 14 points and 11 rebounds - his first double-double. Anfernee Simons chipped in 17 points off the bench. Mobley led Cleveland with 27 points and 14 boards.

Here are four takeaways from Boston’s resilient victory:

After some uneven outings raised questions about his role, Walsh answered emphatically in Cleveland.

The third-year forward was active on both ends, controlled the glass, and scored timely baskets. His 14 points and career-high 11 rebounds anchored Boston during offensive droughts.

His 6 offensive boards fueled 16 second-chance points, crucial for a shorthanded team.

It was a night that showed why head coach Joe Mazzulla trusts him in the starting lineup.

With Queta unavailable, Tillman was unexpectedly thrust back into the starting lineup for the first time in weeks - and showed why he might deserve more looks going forward.

In 30 steady minutes, Tillman put up 9 points, grabbed 6 rebounds, and swiped 3 steals while taking on the unenviable task of defending Mobley.

Despite playing so little in November, he looked composed and physical.

Queta’s impending return will complicate the center rotation, but Tillman gave Mazzulla something to think about.

With White sidelined, Pritchard immediately took on the scoring burden.

He scored 8 of Boston’s first 10 points, survived early foul trouble, and then closed fast-netting 15 of 27 fourth-quarter points, including 10 in the final three minutes.

Efficient, fearless, and relentless, Pritchard delivered his best offensive game when Boston needed it most.

They need 75-80% of that every night from him to have a real shot at making a deep run.

Brown’s shooting was off, but his overall stat line impressed.

He attacked the paint, earning a career-high 16 free throws and hitting 12.

Without his jumper, Brown facilitated, matching a career-high 11 assists while dominating the glass with 12 rebounds.

His complete effort stabilized Boston during Cleveland’s late surge.

Celtics are back in action at TD Garden on Tuesday against the Knicks (13-6).

Tom Carroll is a contributor for Roundtable, with boots-on-the-ground coverage of all things Boston sports. He's a senior digital content producer for WEEI.com, and a native of Lincoln, RI.