WASHINGTON – Two nights after receiving their NBA championship rings and watching Banner 18 ascend to the rafters of the TD Garden before defeating the Knicks in what was essentially one big celebration, the Celtics returned to one on Thursday more monotonous reality.

When their game against the Wizards began, about half of the Capital One Center was full and about half the people were there to support Boston. Fans here understand that the Wizards will once again be one of the worst teams in the NBA this year, and foregoing the opening night, usually full of possibilities, could breathe life into that building.

And the reduced tension seemed to affect the Celtics’ concentration early on, but they made sure it didn’t last. After falling behind by 8 points early on, Boston had little trouble taking control and earning a clinical 122-102 victory.

Jaylen Brown, who turned 28 on Thursday, had 27 points to lead the Celtics (2-0). Jayson Tatum added 25 points and 11 rebounds.

Sam Hauser was out with a sore lower back and there’s a chance he could be sidelined beyond this game. Before the game against the Wizards, coach Joe Mazzulla indicated that he would not necessarily fill Hauser’s minutes by using players of similar size and skill. In fact, he relied heavily on his big men, often using two at a time. The four-man bench that Mazzulla used for most of the evening consisted of three big players: Luke Kornet, Xavier Tillman and Neemias Queta.

Less than two minutes into the first quarter, a referee collided with a fan carrying a tray full of beer, causing the soapy water to splatter all over the hardwood and causing a delay as workers rushed to the scene with towels. Everyone just stood around and waited.

The Celtics seemed to suffer from a lack of energy at the start. They had a few early turnovers, allowed a few offensive rebounds and just seemed out of sync.

It didn’t help that Jordan Poole couldn’t miss. The former Warriors star is an unpredictable shooter but can also catch fire. And he started off by hitting 6 of 8 shots and 5 of 7 3-pointers in a powerful 17-point opening quarter.

The Wizards led by as many as 8 points in the period before the Celtics got behind Tatum.

The Celtics’ first quarter start was pretty aggressive as he did most of his work inside the arc. Eight of his nine shots in the first quarter were two-pointers, and he also attempted seven free throws in the final 66 seconds. Although he missed three shots, his hits were enough to give Boston a 33-32 lead early in the second period.

It helped that the wizards are, well, still the wizards. They fouled Boston’s 3-point shooters twice and committed 10 turnovers in the first half.

Late in the second quarter, Tatum’s eyes widened when 7-foot rookie Alex Sarr joined him. He spun and wobbled twice and had no trouble creating space for threes, the second giving Boston a 60-53 lead. Tatum entered halftime with 20 points and 10 rebounds.

Brown had a quiet 1-6 start but was able to shake it off easily. Towards the end of the second quarter and the beginning of the third quarter, he overwhelmed the smaller Wizards around the basket. After converting a three-point play by pushing Poole back, he leaned forward and held his hand along the floor, the common sign that Poole was undersized.

Brown then finished off the Wizards with two three-pointers in the first 40 seconds of the fourth quarter. After the second, he ran to the baseline and waved goodbye to the crowd.

Adam Himmelsbach can be reached at [email protected]. Follow him @adamhimmelsbach.