PHILADELPHIA — Life comes at you fast in the NBA playoffs — not back-to-back fast but every other day, a pace that’s hectic enough given the stakes involved. That’s how an urgent situation for one team can flip in short order into something even more dire seemingly overnight.

A few days ago, the Philadelphia 76ers were at risk of having their Eastern Conference semifinal series against Boston spiral out of control. Down 2-1 after a couple down games from James Harden, with lingering questions about Joel Embiid’s sprained right knee and limited help from others, the Sixers faced a matinee at home and the prospect of playing for the final time in 2022-23 at Wells Fargo Center.

Uh, never mind. Philadelphia got a performance from Harden (42 points) as impactful as the 45 points he scored in the series opener. Embiid showed up in his Kia MVP cape and, despite a blown lead in the final quarter, the Sixers righted themselves to win Game 4 on Harden’s corner 3-pointer in overtime.

The series reset continued in Boston Tuesday, the Sixers playing their most complete game yet while the Celtics oddly lacked zip, focus or much of a collective shooting eye. Now they are the team at risk of having their season and playoff hopes snuffed on the road in Game 6 Thursday night (7:30 ET, ESPN).

To hear Boston coach Joe Mazzulla tell it in the wake of the Game 5 defeat, his team wanted to win too much.

“I thought we had the intentions of really, really wanting to win and trying to win it, and sometimes when that happens, it has a negative effect,” Mazzulla said. “I think we just have to play with a freer mind, take a deep breath, and regardless of the situation, we just have to be ready to play.”

Here are three other things the Celtics might want to do to force Game 7 in Boston on Sunday:

1. Play faster

Sounds simple, right? But it’s not. A lot of it depends on what the opponent is doing, and so much of what an opponent does is dictated by what a team’s defense is doing. So Boston’s defense has a lot to say about its offense and in Game 5, that largely stayed mute.

“Defense generates good offense,” Celtics forward Jayson Tatum said after the loss Tuesday. “Give it a little more pace to catch them off guard a little bit. When teams score, it can set up their defense and it kind of slows you down a little bit.”

The Sixers shot 50.6% overall and 40% on 3-pointers in Game 5. That enabled them to set up more often in their halfcourt defense, with Embiid to patrol the paint and the other four to move, pester, double or flex anything else in their defensive repertoire.

The Celtics’ attack slowed down. They managed only five fast-break points. And instead of scoring 66 points in the paint the way they had in the series opener, they were down to 36 in Game 5. Going the other way, Boston’s many misses helped trigger Philadelphia’s transition game. Even with Embiid and Harden preferring to walk it up most of the time, the Sixers still got out for 15 fast-break points.

Boston’s Marcus Smart had talked even before Tuesday’s game about the value of pushing the ball.

“It’s not even to score,” the point guard said. “Even if you don’t score, you still run, you still push the pace and you still get something good because now you’ve got the defense on their heels.”

2. Reconsider the double-big lineup

“This isn’t last year” is a common refrain each postseason. What worked before might not work now, ditto for what didn’t work. Still, one of the hallmarks of the Celtics’ run to the 2022 Finals against Golden State was the play of its two biggest rotation players, Al Horford and Robert Williams III.

Horford is the veteran whose versatility never has been more on display than in his late-career role with Boston. He shot a career-high 325 3-pointers this season at age 36 and made 44.6% of them. Defensively, he has been fine coping with other stretch bigs while switching so often in the Celtics’ schemes. Others might have winced when the 6-foot-9 Horford was left on an island to unsuccessfully try to contest Harden’s key three near the end of Game 1, but Mazzulla wasn’t one of them.

Game 6 may be the perfect time to raise Robert Williams III’s playoff minutes,

Williams’ presence was vital against Golden State last June. Constantly hobbled by leg injuries — the defensive ace has never logged more than 61 games in his five seasons, including 35 in 2022-23 — he is a force when healthy or at least able to play in short stints. His rate of blocked shots per 36 minutes, as just one measure of his impact, is 2.9.

Using the two together was something that last season’s coach, Ime Udoka, liked to do. This isn’t last season though, right? Williams’ playing time has dipped in the postseason from 23.2 minutes per game in the 2022 run to 20.6 in 2023. He has been on the floor with Horford for just 57 minutes in 11 games, barely breaking even with a 0.1 net rating per 100 possessions.

But in 332 minutes together during the season, the pair helped to produce a 119.0 offensive rating and 103.1 defensive rating for a net rating of 15.9. Given Embiid’s central role in the Sixers’ attack, two bigs truly might be needed. At the least, it might not have left Tatum backed down by the Philadelphia center late in OT in Game 4, prompting Jaylen Brown to help off of Harden, who immediately made Boston pay with his 3-pointer.

3. Control the other guys

At this point in this series and their careers, Embiid and Harden likely are going to get “theirs” from sheer volume of usage and with legacies on the line. What hurt the Celtics in Game 5 was how productive some of their supporting cast members were.

P.J. Tucker was his usual bruising, irritating defensive presence, while reserve Danuel House Jr. was an inspired deep dive by coach Doc Rivers into the Sixers’ bench for a wild card worth 10 points, energy and defense in 15 minutes. But the real bonus contributors were starters Tobias Harris and Tyrese Maxey.

Harris had averaged 12.5 ppg and 5.8 rpg in the first four games. This time the veteran forward had a double-double by the end of the third quarter, finishing with 16 and 11 to stabilize the Sixers at both ends. Maxey, the hyperactive shooting guard, was wildly inconsistent previously in the series, averaging 16.5 ppg while shooting 36%. In Game 5 he scored 30, hitting 10 of 21 shots overall and half of his 12 3-point attempts.

Harden deserves credit for the way he orchestrated Philadelphia’s attack, making sure both were involved at opportune times. “The Beard” and the MVP also played big roles in making sure Maxey, in particular, was locked in mentally for Tuesday’s game.

“I think I just started out extremely aggressive,” Maxey said. “Jo [Embiid], James, Tobias, they told me the shots I had been shooting [were] pretty good shots. They just haven’t been falling. ‘They’re going to fall for you. We’re not really worried about you. You put the work in.’”

Boston defenders need to put the work in to choke off those third and fourth weapons if they want to fly home with purpose after Game 6.

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Steve Aschburner has written about the NBA since 1980. You can e-mail him here, find his archive here and follow him on Twitter.

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