CLEVELAND — Twice, the Cavaliers threatened to upend the Celtics late.

To upend the series.

To grind Boston’s march through the Charmin soft East playoffs into a shocking halt.

The Celtics marched on in a close call.

Boston clinched its first tight win of the playoffs — and first overall since early April — despite making just two field goals inside the last seven minutes of Monday’s 109-102 victory in Game 4. During that time, Cleveland twice trimmed the Celtics’ lead to five, but never less. The Celtics stayed ahead and seized a 3-1 series lead, grateful to have been tested in the playoffs; even if it was by a wounded Cavs team without Donovan Mitchell and Jarrett Allen.

“Yeah, I think it’s good to be in those situations. It takes what it takes,” Boston coach Joe Mazzulla said of the clutch finish. “However we have to win the game, we have to do it. So it’s good to get reps different ways.”

Before Monday’s 109-102 win in Cleveland, the Celtics beat Miami by an average of 22 points during their first-round playoff series. Last week, they toppled the Cavs by 25 in Game 1 and by 13 in Game 3. Celtics guard Jrue Holiday agreed the experience was positive, despite the fact Boston had been favored by 11.5 points on the road.

“I think it’s just the will to win. We know that they’re not gonna come out and just lay down. We expected this,” Holiday said. “We kind of wanted it.”

Part of the intensity included tense moments between Jaylen Brown and Cleveland’s Max Strus. Brown, after falling to the ground in the first half, felt as though he’d been hit in the back of the head, and reached upward for Strus’ ankle as Strus moved to get back upcourt. Brown’s reach drew a foul call, and boos from the home crowd for the rest of the night.