The Boston Celtics pulled off the rare feat of making 21 3-pointers and losing in Game 3 of their first-round series against the Atlanta Hawks. How did they do it? By losing just about every facet of the game inside of the arc to Atlanta. The Hawks out-rebounded the Celtics 48-29 on Friday. They outscored them in the paint 54-40. Trae Young sealed the game in a close fourth quarter by hitting floater after floater against Boston's conservative drop-coverage in pick-and-roll. The Celtics sorely needed to reassert themselves in the paint on Sunday.

They did just that behind Robert Williams III. The oft-injured big man played one of the best playoff games of his career on Sunday. He finished the night with 13 points, 15 rebounds, two blocks and two steals to help secure Boston's victory. More importantly, those team-wide figures that worked against the Celtics in Game 3 flipped in Game 4. The Celtics out-rebounded the Hawks 49-42 on Sunday, and they outscored them in the paint 56-44.

It was a stellar performance by a player Boston has been hesitant to overuse thus far in the playoffs. In the first three games against Atlanta, Williams never played even 23 minutes. In Game 4, he played 29. He's going to need to maintain that sort of workload in the next two rounds, with Joel Embiid waiting for them and Giannis Antetokounmpo possibly coming in the Eastern Conference Finals. Celtics coach Joe Mazzulla was clear after Game 4 that for the Celtics to reach their ceiling, they'll need more outings like this out of their budding star center.

"Rob's the kind of guy where he's gotta realize he's got a lot of gifts and he's got a lot of abilities," Mazzulla said. "It goes back to what you guys always talk about. Guys need to feel appreciated, need to feel empowered. Every conversation with Rob is about how when he's at his best, we're a different team."

The Celtics are, by and large, a below-the-rim team. Al Horford and Grant Williams have their virtues, but neither offers the verticality or closeout speed that Williams does. That will carry more utility in some matchups than others, but it's a tool Boston needs in its arsenal. Game 3 was a good example of what the Celtics look like when they lose games in the paint. Williams made sure it didn't happen again in Game 4, and now the Celtics are only one win away from the second round.