OKLAHOMA CITY — The photo captured a moment of pure jubilation, with Matisse Thybulle raising his arms to high-five Furkan Korkmaz and Georges Niang, mouth agape, pressing both hands to the side of his head in disbelief.

Niang called it a natural reaction to “Furkan Magic,” when Korkmaz drilled a deep three-pointer as part of an 18-point fourth-quarter explosion to turn a competitive 76ers season opener in New Orleans into a blowout. That was just a glimpse of what coach Doc Rivers hopes this Sixers second unit can be at its best, making “growing” that group an early-season priority.

“Letting them try to figure [it] out … that pays dividends later,” Rivers said. “That’s why, early in the year, you extend your bench. That’s why you do it. It’s so important for your team.”

That group did its job in Sunday’s 115-103 victory against the Thunder. A lineup of Korkmaz, Thybulle, Niang, Isaiah Joe and Paul Reed took the floor together with an 87-78 lead at the start of the fourth quarter and rapidly increased it to 18 points with an 11-2 run in the frame’s first three minutes. When Reed grabbed an offensive rebound and dished the ball to Niang for the three-pointer that put the Sixers up 98-80 with 9:49 to play, their teammates on the bench erupted.

“That’s what we’ve been talking with him all year about,” Rivers said of Reed, who finished with five rebounds, two assists, one block and two points in nine minutes Sunday. “Hey, listen, you’re undersized. You’re trying to score in the paint over three guys. You’ve got shooters all around you. Just throw it back out. That’s why, when he did and they called a timeout, everyone was giving him a hug.”

It was a positive teaching moment for a second-year big man as part of that ongoing quest. Developing those reserves is an appropriate goal for a Sixers team that recently has squandered leads, most crushingly against the Atlanta Hawks in the Eastern Conference semifinals, or was forced to bring the starters back because the reserves could not put the game away. Rivers called last season’s bench play “very inconsistent,” and called for that unit to be more efficient in 2021-22.

Last season, the Sixers ranked 13th in the NBA (eighth among playoff teams) in bench scoring (37.3 points per game), 11th in plus/minus (plus-0.7), 19th in field-goal percentage (44.6) and 25th in turnovers (5.7 per game). During the playoffs, they were third in bench scoring (30.3 per game) but were sixth among the eight teams that made it past the first round in plus/minus (minus-0.8).

Bench production has also already become a necessity during the season’s opening week.

Ben Simmons’ situation has vacated a rotation spot until it is eventually filled by him or whoever comes back to Philly in a trade. Reed was in the game Sunday because Andre Drummond was out with a sprained ankle, and Joel Embiid continued to nurse knee soreness that prompted the MVP contender to take a longer second-half break in Friday’s last-minute loss to Brooklyn. Reserve guard Shake Milton also remains out with a sprained ankle, bumping Joe to regular minutes.

Rivers’ approach to using all-bench lineups for significant stretches has drawn some outside criticism. But the coach says it is necessary to build confidence in players who will need to step up periodically during an 82-game grind, like Reed in place of Drummond on Sunday night.

The long-term impact also benefits the starters. Point guard Tyrese Maxey was the only first-teamer to reenter the opener in New Orleans in the fourth quarter, allowing for rest that was more important than initially realized because of Embiid’s banged-up knee.

“Those minutes add up,” said guard Seth Curry, who has been a starter and reserve at different points in his career. “If you bring your starters back a little earlier one or two games here and there, it’s not that big of a deal. But if you’ve got to do it every night and if you’re always worried about, ‘Are we gonna keep our lead?’ or ‘Are we gonna stay in the game without them out there?’ it’s tough.”

Added Niang: “You really try to build the trust of the coach, knowing that he can keep you in longer.”

Rivers praised the second unit throughout camp for its ball movement and defensive intensity, saying that group regularly outperformed the starters during scrimmage and 5-on-5 work. In general, the coach said, “good things are happening” when the reserves are on the floor. So far, game results have been mostly positive in a very limited sample size entering Sunday’s outing against the Thunder.

Before the second-half onslaught in New Orleans, the group’s initial stint resulted in six of the Sixers’ eight first-half turnovers. Against the Nets, the bench held the lead in the second and fourth quarters — paced by Korkmaz’s 10 points, Drummond’s 10 rebounds, two blocks and two assists and Thybulle’s three assists — before the late collapse with the starters primarily on the floor.

In the second quarter against the Thunder, the all-bench unit maintained a double-digit lead, highlighted by Niang’s old-fashioned three-point play and shot from beyond the arc to increase the lead to 44-31. Rivers commended the way the group handled the way the like-sized Thunder players switched everything defensively, saying Oklahoma City “made it one of those [ragtag], tough games, and I thought our guys prevailed. I thought they all did.” Philly finished the night with 26 bench points, led by Niang’s 12, and nine bench assists.

Rivers called Drummond and Niang, the group’s frontcourt newcomers, the players that “spearhead the spirit and the emotion in how the bench plays.”

» READ MORE: Sixers vs. Thunder instant analysis: Seth Curry sparks 115-103 win in Oklahoma City

Though Rivers said Drummond still needs to find a balance between passes that are slick and too much of a risk, the big man has displayed the athleticism and hustle to go airborne to swat away lobs, roll hard and rebound in an exceptional way that prompted star Tobias Harris to call Drummond “a steal for us.” Niang, a quintessential stretch-4, had made four of his nine three-point attempts entering Sunday’s game in Oklahoma City and provides a calming presence. Without Drummond Sunday, Niang played a spurt behind Embiid before Reed entered the game at the start of the second quarter.

On the wing, Thybulle is one of the NBA’s top perimeter defenders and a classic example of a player whose imprint on a game does not always appear in the box score. Joe, a second-year guard, was one of the Sixers’ best players during the preseason because of his red-hot shooting and defensive activity but has struggled in the first two regular-season games.

Korkmaz, meanwhile, has been an engine of sorts as the de facto backup point guard with Milton sidelined. He plays that position with the Turkish national team and knew that ability was “in my pocket. I just never had a chance to use it.” He has worked every offseason on his ballhandling, including keeping his dribble low since his 6-foot-7 frame is taller than most point guards.

“First couple years in the league, you’re trying to get your spot in the rotation,” he said. “You’re trying to play with what coach is giving you, and mostly for the young guy this is just spot-up, catch-and-shoot threes and then playing defense without mistake. That’s what I did almost my first three years, but right now Doc is trusting me. He’s giving me a lot of confidence, too.

“He wants me to make play. He [doesn’t just] want me to score. He wants me to make plays for others. I think this year, especially, I understand that much better than last year.”

Yet Korkmaz will still fire away when he’s in a rhythm like he was in Wednesday’s opener. In the midst of that 18-point flurry, he spotted Maxey in the corner, but said to himself, “I’m gonna shoot this” from way beyond the arc.

Korkmaz buried the shot, and the jubilation captured in that photograph ensued.

The best part for the Sixers? No starters were in the photo, because their celebration originated from the bench.

“It was a different story last year,” veteran starting wing Danny Green said. “Our bench was something we had to try to figure out. This year, they’re a plus and they’re rolling.”