That was the Mavericks’ best chance to steal a game. The Celtics didn’t let them seize it.

Any team, at any level, can win pretty.

When the ball is zipping from side to side, shots are falling and vibes are high, basketball’s really a rather pleasurable game.

But when shots clang off the rim, and percentages dip lower and lower, it can be quite frustrating. What separates championship teams from the pack is often their ability to grind out ugly wins under those circumstances.

On paper, the Celtics had no right to win Game 2. Boston shot 25.6 percent from 3-point range, shot a lower percentage from the field and lost the rebound battle.

Jayson Tatum finished 6 of 22 from the field and 1 of 7 from 3 (yes, he did everything else quite well). Jaylen Brown turned it over six times and posted a negative plus-minus. Al Horford was basically invisible. Sam Hauser didn’t make a shot. Luka Doncic had a 30-point triple-double. All five Mavericks started scored in double figures.

The list goes on and on and on…The Mavericks probably “should” have won this one. In a series where they’re objectively outmatched, Dallas won’t have many chances. This felt like one of the few.

So, how did Boston pull out a gutsy 105-98 win? A combination of adaptability, grit, coolness in the clutch and more.

“That’s the key. That’s the majority of what the battle is,” Brown told reporters. “It’s just managing your emotions. How do you handle adversity and your will and your perseverance?”

Oh, and Jrue Holiday contributing 26 points (11 of 14), 11 rebounds, 3 assists, 1 block and 1 steal didn’t hurt. That guy is something else. If you created a player in a lab to pair with Brown and Tatum, the output would basically be Holiday. He flashes at the right moments, is a magician in the paint and has pristine footwork. That’s just on offense. Defensively, he’s a whiz and constantly makes life difficult for the opposition. The moment’s never too big.

Derrick White also made countless timely plays, hitting big shots, wreaking havoc defensively and serving as the glue as he so often does. He may not want to take credit for his acrobatic blocks, but there aren’t many plays that electrify the Celtics and their fans more than a well-timed White rejection.

Tatum has had better games. He’s been more effective as a scorer. He’s played with more of an edge. But this game showed how far he’s come as an all-around player. He didn’t take Jason Kidd’s bait and continued to make the right read. When he had one guy on him, he shot. When he drew two or three, he passed. You don’t rack up 12 assists without doing something right. Along those lines, you know you’re pretty good when you have 18, 12 and 9 in a Finals game and people still want more.

Brown had seven assists, Kristaps Porzingis was a menace on both ends and Payton Pritchard hit the biggest shot of the series so far to end the third. That moment sums up what this team is all about. All season long, the Celtics have preached sacrifice and togetherness. They haven’t just talked the talk; they’ve walked the walk.

They’re playing with the sense of unity and urgency you expect to see from a team in the Finals.

“I think we played harder than them tonight, and that has to be the key,” Brown told reporters.

Teams in years past have had talent, but a sense of apprehension inevitably emerged when the game was on the line. You wanted to believe, but you worried they might crumble. This team is different. When everything’s on the line, you have faith that they’ll get it done. That’s special.

Part of the reason we all love basketball so much is because it oftentimes mirrors life. You stumble, you fall, you fail, but you learn from it. It makes you stronger in the long run. The Celtics have dealt with failure, and that misery has fortified them forever.

The reason they pulled out Game 2 had very little to do with Xs and Os. It boiled down to heart, chemistry and a desire from deep within. The Celtics can see that the finish line is near, but they there’s still work ahead of them.

“The journey to this point has been great,” Holiday told reporters. “But we know being up 2-0 means nothing. Job’s not done. We have to do whatever it takes.”