OKLAHOMA CITY – This one had to be tough.

The 76ers checked all the offensive boxes that their coach Brett Brown doubled-down on and still lost.

The Oklahoma City Thunder made 5 of 7 shots and all eight of their free throws in the extra session en route to posting a 127-119 overtime victory over the Sixers Friday night at Chesapeake Energy Arena.

Danilo Gallinari (seven), Shai Gilgeous-Alexander (six), Chris Paul (four) and Terrance Ferguson (three) combined to score the Thunder’s 20 points in overtime.

The Sixers committed six personal fouls in the overtime session and 32 for the game. Taking advantage, the Thunder made 35 of 41 foul shots.

Paul went 12-for-12 from the line en route to finishing with 27 points. Gallinari was 11-for-11 from the stripe, finishing with a team-high 28 points. And Gilgeous-Alexander had 24 points, making 5 of 6 free throws.

Tobias Harris fouled out with 2 minutes, 48 seconds left in the overtime. Meanwhile, Ben Simmons did the same with 1:03 left in the extra session.

“I think there has to be a better awareness of bonus stuff,” Brown said of the fouls hindering what the Sixers tried to do down the stretch. “I think there needs to be a better discipline of not taking swipes at things when you’ve got to show your hands.

“I thought there were some hard-luck fouls that might be questionable. But at the end of the day, you look at this, I think it points to us fouling.”

The setback dropped the Sixers to 7-5 and marked their second straight loss and fifth in seven games. Prior to beating the Thunder here on Feb. 28, 2019, the Sixers’ last win over OKC was on Nov. 15, 2008, in Philadelphia. It was the teams’ first meeting after the Seattle SuperSonics moved, changed their name and relocated to Oklahoma City.

The Sixers dropped to 1-10 in games against the Thunder (5-7) in OKC.

On Friday morning, Brown said his team’s shooting woes were an “outlier” and “abnormal.”

“Like we can all do what you do and so I do, but you cut to the chase," he said. “The extraordinary drought that we have been in is rare.”

Doubling down on his comments, Brown didn’t want players to be “gun shy” from shooting three-pointers, despite going a combined 16-of-68 from that distance in the previous two games.

On this night, Harris and the Sixers as a whole broke out of their slumps.

Harris finished with 21 points on 8-for-16 shooting to go with six rebounds and three assists. The forward made 3 of 4 three-pointers and made a three-pointer on his first shot attempt, snapping his streak of 23 straight missed three-pointers.

Meanwhile, the Sixers made 14 of 32 three-pointers for 43.8 %.

Joel Embiid had 31 points and 12 rebounds. The two-time All-Star center went 4-for-8 on three-pointers. Josh Richardson finished with a season-high 28 points on 10-for-15 shooting -- including going 3 of 6 from deep. He scored 11 of his points in the third quarter of his homecoming. The shooting guard grew up 15 minutes north of Oklahoma City, in Edmond, Okla.

The Sixers opened the game by making their first five shots to take a commanding 12-3 lead. They made two three-pointers during that stretch.

Harris made the first oneand Embiid hit the second three-pointer, from 29 feet out.

However, the Thunder battled back and took their second lead of the game, 33-32, on Terrance Ferguson’s layup with 7:53 left in half. OKC opened up an 8-point lead early in the third quarter. But the Sixers responded and opened up a five-point lead late in the quarter.

In a game of runs, OKC came back and took a 97-96 lead on Gilgeous-Alexander’s layup with 3:38 left. The lead seesawed before Paul hit a pair of foul shots to give the Thunder a 101-98 lead with 2:45 to play. The Sixers knotted the score at 105 on Embiid’s three-pointer with 1:07 left.

The teams then traded foul shots on the ensuing possessions before Embiid’s missed 20-footer with 5.6 seconds left that didn’t draw iron. The Sixers committed a shot-clock violation, giving the Thunder the ball with 3.9 seconds remaining.

Gallinari missed a 24-footer as time expired and the teams went to overtime tied at 107.