This time, the Brooklyn Nets didn't need to erase a deficit in the fourth quarter. They didn't need Kyrie Irving to hit a series of preposterous, contested shots against the best defense in the NBA. Coming out of a timeout with 9:47 left in Game 2 of their first-round series against the Boston Celtics on Wednesday, the Nets had a five-point lead and an opportunity to go home with a split. 

Brooklyn, despite its small backcourt, was winning the possession game: It had attempted one more field goal and one more free throw than Boston and had similarly slight edges in second-chance points, fast break points and rebounds. The Nets' offense hadn't been particularly pretty, but they were efficient enough and their defensive game plan was more or less working. Grant Williams and Al Horford were the Celtics' two top scorers; stars Jayson Tatum and Jaylen Brown had combined for 24 points on 8-for-26 shooting and seven turnovers. 

Kevin Durant checked in for the stretch run, and then everything went wrong. Brooklyn's lead, once as large as 17, vanished almost immediately. In less than eight minutes, Boston went on a 21-4 run, during which the Nets missed 10 of the 12 shots they attempted. They did not make a 3 or attempt a free throw. They did not force a turnover or score in transition. 

The 114-107 loss could be seen as a teachable moment for a team with little corporate knowledge or the moment at which Brooklyn was doomed to spend another summer playing the what-if game. At Durant's post-game press conference, a reporter noted that both games at TD Garden were there for the taking. What must be done in these situations? 

"We just gotta finish it," Durant said.

How did an offense with such firepower fall apart? Pretty much how you'd think. It turned into a matchup-hunting game, and, while the Nets have otherworldly hunters, they had less favorable matchups. The Celtics, with all of their size and smarts and switchability, baited them into tough 2s over and over again. Boston went at their small guards on the other end and scored virtually every time, preventing them from finding easy buckets on the break.

As soon as Durant got back on the floor, he back-rimmed a midrange jumper off an after-timeout play. It was the kind of shot he has made a million times, but it was well contested and Brooklyn was lucky to come away with the rebound. Seth Curry tried to take Williams and then Horford off the dribble, but couldn't convert with his left hand. 

The Nets continued to target Williams, a sturdy, 6-foot-6 forward, without success. Irving dribbled out of a double-team and missed a pull-up 2, rather than making Boston pay for abandoning Andre Drummond in the paint and Goran Dragic on the perimeter. Durant danced with the ball beyond the 3-point line, only for Williams to poke it away, out of bounds, off Durant, his sixth turnover of the game.

Brooklyn's most surprising offensive possession was the one in which Drummond put the ball on the floor near halfcourt, hit Williams with a crossover and kicked the ball out to Curry. Irving screened for Durant on the other side, but since the Celtics' like-sized stars were on them, it was a simple switch. Bruce Brown might've had a dunk if he'd cut from the corner, but instead he spaced and misses a 3 over Williams. Again the Nets wasted an offensive rebound, as Tatum and Horford swarmed Irving and forced a turnover. 

The most ill-advised shot came from Durant, who shot 0 for 10 in the second half. Attempting to end Brooklyn's five-minute scoring drought, he forced a midrange jumper with both Tatum and Jaylen Brown converging on him. Tatum blocked it.

The confusing part is that, for most of the fourth quarter, Boston had Payton Pritchard on the court and the Nets didn't pick on him. Instead, there was Durant trying a turnaround against Jaylen Brown, then Irving missing a layup with Williams contesting from behind:

When Pritchard went to the bench, both Irving and Durant resorted to off-the-dribble jumpers against Horford. These aren't bad looks for those guys, but when they're the best looks you can get, the defense is doing its job. Brooklyn wants to make the defense move, make the defense think and use all the attention the Durant and Irving attract to create easy looks for shooters and slashers. When the Nets are in the flow, the superstar shots are more deflating.

Brooklyn coach Steve Nash said that the team's intensity dropped after halftime. "We also didn't convert," he said. "We had a lot of opportunities." Maybe, if the Nets had been able to get a timely bucket or a timely stop, they could have avoided a full collapse. They know that the Celtics are positioning help defenders at the nail and switching to keep the ball in front. They know that Durant and Irving can counter this with crazy shot-making, but that it's not wise to rely on that -- especially now that they need four wins in five games.

"We just gotta be -- the supporting cast has gotta be better for 'em," Bruce Brown said. "Cut, get off the wing and just be ready to shoot the ball."

Irving said he "didn't touch the paint as much as I wanted to tonight," and Durant said that he has to "be more patient, but also play fast sometimes, too." If Brooklyn goes down in the first round, the story will be straightforward: It ran into a more cohesive, more connected, more complete team, with the defensive personnel to smother its stars. The Celtics had those advantages when the Nets trailed for most of Game 2, though, and the same was true when the opener went down to the wire.

"We'll figure it out," the ever-confident Bruce Brown said. But Brooklyn's margin for error is shrinking fast, and, much like those contested pull-ups, it would like Ben Simmons' reportedly forthcoming return to be a bonus, not a necessity. Maybe the Nets will be in another tight game on Saturday at Barclays Center, and maybe they'll find a way to finish it. 

If not, they're finished.