Sunday night’s contest could be a defining moment for 76ers coach Doc Rivers.

The Sixers will entertain the Atlanta Hawks at the Wells Fargo Center in a winner-take-all Game 7 of the Eastern Conference semifinals. For Rivers, this marks his NBA-leading 15th Game 7 as a coach.

The 59-year-old is 6-8 in Game 7s, including a 6-4 home record.

Rivers said “execution and trust” are the two keys to prevailing in Game 7s.

“At the end of the day, trusting what you’ve done all year,” he said. “Not getting away from it. I think in the games that I’ve won, I felt that my team, for the most part, stayed with what they had and trusted.

“In the games they lost, for the most part, they didn’t.”

Rivers acknowledged that there were a couple of Game 7s where the other team was better. There was nothing he could do. But there were a couple where he thought his squads were better.

“So it all works out,” Rivers said.

This is a big game for him as well as standouts Joel Embiid, Ben Simmons, and other holdovers from the Sixers’ 2017-18 and 2018-19 seasons. They’re determined to get out of the second round for the first time in three tries.

The Sixers lost in five games to the Boston Celtics in 2018 before losing to the Toronto Raptors in seven games in 2019.

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They’re looking to win a second-round series for just the second time in the franchise’s last 11 appearances, dating back to 1986. Their last win came in 2001 when they beat the Raptors in seven games en route to finishing as NBA Finals runners-up.

Rivers also has had issues in the second round, unable to advance to the conference finals while coaching the Los Angeles Clippers the previous seven seasons before coming to Philadelphia. But in 2008, he led the Boston Celtics to an NBA championship over the Los Angeles Lakers. His Celtics would lose to the Lakers in the Finals in 2010, and reached the conference finals two seasons later.

Rivers led the Clippers to six postseason appearances in his seven seasons in Los Angeles. They lost in the second round three times. The last two -- 2020 and 2015 -- they were a game away and failed to advance, blowing a commanding 3-1 lead both times.

As for Rivers’ last Game 7 coaching victory, that was in the 2014-15 Western Conference first-round playoffs when the Clippers defeated the San Antonio Spurs. He is 0-3 since.

NBA fines Embiid $35,000

Earlier Sunday, the NBA announced Embiid was fined $35,000 for escalating an altercation by pursuing Atlant Hawks forward John Collins late in Game 6 and did not comply with an NBA security interview following the incident.

Meanwhile, Hawks forward Bruno Fernando was suspended for one game without pay for leaving the bench area during the altercation. He will miss Game 7.

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Embiid was called for an offensive foul while appearing to score a basket on Collins in the paint with 4 minutes, 2 seconds remaining.

After both players fell to the floor, with Embiid falling on top of Collins, Collins shoved Embiid off him and began yapping at Embiid. The players got up and Embiid took steps toward the Hawks’ power forward. Embiid, while extending his arms, forced Collins off the court and to the side of the basketball stanchion. Both players received technicals.