BOSTON — It doesn’t always work out this well, but when Leandro Barbosa finds a groove, the points flow like water.

Consider the Boston Celtics guard’s entry into Sunday’s overtime victory at Orlando. On successive possessions he nailed a 3-pointer and then, off the break, a running banker that extended into a three-point play.

The elapsed time from 3-pointer to free throw was 21 seconds.

The burst was a repeat of his first-quarter offense after replacing a temporarily foul-dinged Rajon Rondo. He buried a 3-pointer with 56 seconds left, and 29 seconds later split the lane with a left-handed drive.

Overall, first- and second-quarter bursts combined, Barbosa scored 11 points in roughly three minutes. Of course this dynamic can swing the other way. Barbosa’s next time down the floor following his three-point play, he was whistled for charging.

Still, Barbosa’s scoring can be the perfect boost for a sagging offense.

“We thought he was going to go for a record in the first half. He’s a scorer,” said Coach Doc Rivers. “We don’t have a backup point guard right now, so when we put him in we put him in as a scorer. I tell our team that when (Barbosa) is in the game and Rondo is off the floor, we have two 2-guards in the game. And so everyone’s a scorer. And when we run the pick-and-roll with him, he’s running to score and not to be a passer. He understands that role.”

Perhaps this is why Barbosa, unlike some other new Celtics, hasn’t needed to explore to find a niche. The rim is his focus, though Barbosa denies he looks at himself strictly as a scorer.

“That’s my game. I like to be aggressive every time I’m on the court,” he said. “Coach has been giving me a lot of confidence, so every time I’m there, of course, I try to set up plays for my teammates, but if I see an opportunity to score, I will score.

“I am (comfortable), but the reason is because of my coaches and teammates. They give me a lot of confidence out on the court. They help me a lot. I’m very happy about that.”

That feeling has been reciprocated.

“That’s why we brought him in,” said Rondo. “We know he can score the ball, and (Sunday night) he scored in four or five minutes. He picked up some fouls but he still dominated the game. To have a backup point guard come in and have that kind of effect is big for me and our team.”