NEW YORK — Doc Rivers began his Thursday evening by taking a moment to consider the human condition. Specifically, the parts of our brains that might be prone to complacency, to relenting … and, in the case of his 76ers, to easing off the gas a bit after two straight wins against the overmatched and outgunned Nets had Philadelphia halfway to a sweep and the second round of the 2023 NBA playoffs.

“Well, it’s hard, you know?” Rivers told reporters before Game 3 at Barclays Center. “You're fighting human nature. You just are. Doesn’t matter how many times you guys write it, how many times the coaches say it. It still comes down to the human element. … We didn't get in the playoffs to win two games and have a celebration, you know? We have a lot of wins left to get where we have to go, and so until we get those, you should be hungry and ready. But human nature does play a part, so we'll find out.”

The human element made its presence felt early, often and overwhelmingly in a Game 3 that included 30 personal fouls, two flagrant fouls, two ejections and too many chaotic moments to count. It was the kind of game Rivers grew familiar with during his playing days; asked afterward if he’d ever been involved with one this wild, he quipped, “I played for the Knicks. Go watch Phoenix-Knicks.” It was the kind of game that, to a hard-charging grinder like P.J. Tucker, felt like “home.”

And while it wasn’t nearly as pretty as many of the performances that Philadelphia stacked up behind its pristine two-man game and the individual brilliance of its MVP favorite, it was, at the end of the day, a win — a 102-97 victory that gave the Sixers a commanding 3-0 lead over the Nets, a deficit from which no NBA team has ever come back. They’ll have the chance to eliminate Brooklyn on Saturday and advance to the conference semifinals for the fifth time in six seasons.

Just how much confidence Thursday night should inspire in Sixers backers, though, is something of an open question.

The most dominant force in the series came within a hair’s breadth of getting chucked less than three minutes into Game 3. Joel Embiid momentarily lost his cool, and perhaps his mind, by lashing out in frustration following an Iversonian stepover with a kick to Nic Claxton’s nether regions; he narrowly avoided ejection, receiving a flagrant 1. While Embiid got to play on, though, his impact felt more muted than usual. He remained great defensively, and Philly outscored Brooklyn by four points in 38 minutes of work, but he scored just 14 points on 13 shots, with a pair of assists against five turnovers and precious little of the ferocious dominance he so routinely displayed during the regular season.

Some of that’s owed to Brooklyn’s ongoing commitment to double- and triple-teaming Embiid to force the ball out of his hands. (For what it’s worth, he did log four secondary assists for passing the ball out of all that pressure to set up an open shot for a teammate.) Some of it likely stems from the back pain that sent him back to the locker room for treatment late in the first quarter, or the knee pain that clearly had him laboring later in the contest — ailments exacerbated by persistent knocks from a desperate Brooklyn team intent on mitigating its size and talent deficit through increased physicality.

“You know, the whole game, you could see what they were doing — just trying to get a rise out of me,” Embiid said after the game. “I'm too valuable. Especially after the first one, I just understood: I'm too valuable to get into, you know, this stuff. That’s the second time, you know, hitting me in the back, that’s not reviewed. My back, my knee, they’re hitting me every single time. Which is fine. It’s working for them. But you’ve just got to keep going, and you could see, you know, what the game plan was — gotta hit him, got to make me frustrated so I could get ejected. I’m too mature to put myself in the position where I’m going to get ejected.”

James Harden wasn’t as fortunate as Embiid: His off-hand strike below the belt of Nets swingman Royce O’Neale did earn him a flagrant 2 and an early trip to the showers. It was an ignominious end to Harden’s best performance of the series, with 21 points in 29 minutes and a handful of makes inside the arc; it was also a fitting finish to a third quarter in which Philadelphia almost completely unraveled, committing nine turnovers in the frame to help fuel a 23-7 Brooklyn run that gave the hosts a lead entering the fourth quarter.

Claxton later fell prey to his own fit of pique, when his post-dunk-on-Embiid celebratory mean mug got him a technical foul for taunting — his second of the game, sending him to the locker room and ending his best performance of the series with more than eight minutes to go in regulation. Brooklyn led 87-82 when Claxton was ejected; Philly would outscore the Nets 20-10 over the final 8:48 that he missed.

“I mean, you can look at the plus-minuses, right?” Nets guard Spencer Dinwiddie said after the game, when asked about the impact of Claxton’s ejection. “He's the only one positive, and he's very positive.”

Depending on your point of view, you might think the humans on whom many fans focus most feverishly — the officials — botched one, some or all three of those situations. Harden said he got no explanation of why his incident with O’Neale merited an ejection and called the decision “unacceptable.” When I asked Tobias Harris for his view on it after the game, he smiled and said, “My reaction was that I don’t want to be fined by the NBA, so I will not say anything about that.”

Of Embiid’s kick to Claxton, Nets coach Jacque Vaughn said he didn’t think he’d “ever seen that in my career before: for a guy to intentionally kick someone in an area that none of us want to be kicked at, or toward, and for him to continue to play.” Embiid played coy after the game, claiming not to remember what transpired, insisting that “it takes me a while to process a game, you know, after that type of fight.” Asked afterward if he remembered the play where Claxton got the gate, though, the big fella replied, “Um, yes,” before flashing a broad smile.

(For the record, crew chief Tony Brothers told a pool reporter after the game that Embiid’s kick received a flagrant 1 because while “the contact was deemed unnecessary … it didn’t rise to the level of excessive,” because they judged that “the point of contact” was Claxton’s leg, not his groin. Because Harden’s hit, on the other hand, was “directly to the groin, it rose to the level of excessive and ejection.”)

With Brooklyn trying to avoid a 3-0 hole, and the Sixers breathlessly trying to avoid any of the rakes they seemed determined to step on all night, the intensity reached a fever pitch, resulting in exceedingly wild sequences like this one in the middle of the fourth:

The Sixers got over the finish line on Thursday, thanks to the hot hand of young guard Tyrese Maxey, who scored 10 of his team-high 25 points in the final three-plus minutes and dotted Dinwiddie’s eye with a go-ahead pull-up 3-pointer in the final minute; to Embiid, who swatted Dinwiddie’s would-be game-tying layup with 8.8 seconds to go; and to Brooklyn’s communication breaking down at the worst possible moment, as O’Neale threw away a pass intended for Mikal Bridges, which De’Anthony Melton picked off and turned into a runout dunk to seal the win.

The glass-half-empty view would focus on the fact that Embiid, for all the praise of how patiently he’s processing Brooklyn’s double teams, has made just 18 shots through three games and has more turnovers than assists. Or Harden’s ongoing struggles to finish against length on the interior — an issue that Rivers chalked up before the game to failures in Philly’s half-court spacing, but that also looks to have a lot to do with a lack of burst and lift once Harden tries to elevate around the rim. Or the fact that the Sixers have needed Maxey to shoulder the scoring burden twice — in the first half of Game 2, in the fourth quarter on Wednesday — and Tucker to relentlessly generate extra possessions on the offensive glass just to put away a Nets team that is an order of magnitude less talented than they are.

There is a glass-half-full take, though. That they’ve needed Maxey and Tucker — and Harris, who bully-balled his way to 15 points and seven rebounds, and Melton, whose defensive activity and complementary playmaking continue to be a godsend — to do more isn’t as important as the fact that those guys have done it, that they’re playing their roles as intended. And that, even against an opponent dedicated to preventing Embiid from getting loose and on a night when, as Rivers said after the game, “We didn’t have our stuff,” the Sixers still won.

That, to hear Tucker tell it, breeds character.

“I told Joel before we started the playoffs: These type of games are the ones you remember, if you get to where you want to be,” he said. “Those games where you shoot 40%, and 60 from the free throw, and nobody can hit a three, and you win? Those are the ones. That's when you know you’re growing as a team — when you do whatever it takes that night to get the win. And these are the kind of games that, you know, build that foundation to be able to win. Because then, when you're rolling, it's hard to beat you.”

It’s even harder when you don’t beat yourself — when you clean up the turnovers that give the underdog oxygen, when you steer clear of the petty beefs and unnecessary conflicts that can result in techs and flagrants, and when you take care of business at your first opportunity rather than playing with your food.

The Sixers need to approach Saturday’s Game 4 like they have no margin for error and have to play their sharpest ball of the series, because the sooner they close this series out, the sooner Embiid can prioritize rest and treatment on the lower back and right knee that clearly appeared to be ailing him during Game 3 in hopes of having him as close to full strength as possible for a potential second-round matchup with a dangerous Celtics team. Sterner tests lie ahead; Philly’s got to ace this one, though, before it can confidently consider itself a team that can pass the rest.

“Who knows, man? Everybody think they got a chance right now,” Tucker said. “There's no rhyme or reason. Everybody can feel good — you win a game and now you think you can win it [all]? But it's still such a long road, and that's my communication to my team right now. We just worry about one game at a time. We can't look ahead and can't start to think about certain things. Let’s win today and we'll worry about tomorrow when we get there. Our minds have to be here, today — right now, locked in, each game, every night.”

Complacency’s part of human nature, but it’s a part that a Philly team with championship aspirations can ill afford to entertain. Just because you have a 3-0 lead, that doesn’t mean you have to play like it.