Boston Celtics guard Marcus Smart highlighted how the bumpy journey to this point is what makes his team so unified, after they produced a near-perfect defensive fourth quarter to defeat the Golden State Warriors 116-110 in Game 3 of the NBA Finals.

The win gives the Celtics a 2-1 series lead, with a chance to go up 3-1 by holding serve at home in Game 4.

In the process, the Celtics core of Smart, Jayson Tatum and Jaylen Brown became the first trio since Kareem Abdul-Jabbar, Magic Johnson and Michael Cooper in 1984 to all have at least 20 points, five rebounds and five assists in a Finals game.

The Celtics needed to get up off the canvas after a trademark Golden State Warriors third-quarter run saw them claw back from a 12-point half-time deficit to take an 83-82 lead with just under four minutes remaining in the third.

In response, the Celtics held the Warriors to just 11 points in the fourth quarter, completely shutting down one of the most dynamic offenses in league history to lock up the win at home.

Smart, who has been criticised for trying to be too involved in the Celtics offense while neglecting his point guard duties, credited his star team-mates for helping him believe in his own scoring ability.

"The 'Jays' – Jayson and Jaylen – have done a really good job of encouraging me to be aggressive on the offensive end," he said. "And really understanding that for me, in this team, I have to be aggressive to help us win."

Smart's relationship with the 'Jays' goes deeper than basketball, and he said it took some growing up, as well as some tough conversations for the trio to become who they are today.

"First off, this is a family here," he said. "I grew up with the Jays.

"I've been playing five years with Jaylen, four years with Jayson. When my mom passed… they all came down to the funeral, so we've already had that bond.

"Early on in the season for us, it's just like it is with your siblings. 

"You get into it, you squabble, you're mad at each other – and then the next day you're laughing, talking, hugging… giving each other their roses, and that's what this team is.

"It started off shaky for us, but that right there is what helped us get to where we are now. We had to go through the storm to see the rainbow at the end of it.

"For me, I had to look myself in the mirror. Along with my team-mates, we had to have a heart-to-heart, we had to sit down and have that hard talk, and understand that what we're saying is to help each other.

"It's nothing bad, it's nothing personal, it's to help us get to where we want to be. It's crazy, we're here, and nobody thought we would be here… but we stayed with it, and that's why I'm proud of this team, and it's what makes us who we are."

The Celtics have done plenty of soul-searching this season, and it was the case again after a demoralising Game 2 loss, but Smart said he was determined to not let the Warriors "bully" his side.

"We pride ourselves on being a physical team, and for us, [Game 2] left a bad taste in your mouth," he said.

"Coming out of Game 2, hearing and knowing that we got beat up. It's just like anybody else, if you're in a fight with a bully or anything, you've got to keep going, you've got to stand up."

When asked if he feels like the Celtics are in a fight with a bully, Smart replied: "We definitely are, we got the Golden State Warriors, who have done this before, multiple times, and they understand what it's like to be here.

"We're that little guy that is new to the school, and they want to see exactly what you've got. They came out and punched us in our mouth in Game 2, and we responded.

"We watched the film – and that was a nasty film session for us. It was ugly, we had to sit there and watch the whole film.

"You have to look yourself in the mirror and get it together. Coming out today it was not a matter of 'are we going to be physical' – it was 'how physical are we going to be'."