Before Game 2 of the Eastern Conference opening-round series with the 76ers, Brooklyn Nets coach Kenny Atkinson was expecting the Sixers to come out full force after their Game 1 clunker

“We expect a haymaker,” Atkinson said. “We know it is coming.”

It came.

Maybe not an early knockout punch, but plenty of effective body blows and then the haymaker arrived with a 14-0 run to begin the third quarter. The result was a 145-123 win over the Nets on Monday, evening their best-of-seven series at one game apiece. The 145 points set a club playoff record.

Game 3 is 8 p.m. Thursday in Brooklyn.

Looking from a history perspective, this was basically a must-win situation for the Sixers. They have never overcome an 0-2 deficit in a playoff series.

Now they don’t have to worry about that.

Leading, 65-64, at halftime, the Sixers got their transition game going in scoring the first 14 points of the second half.

Joel Embiid, who scored 10 points in the first half, added nine in that 14-0 run. He finished with 23 points and 10 rebounds.

The lead expanded to 116-87 by the end of the third quarter. The Sixers outscored the Nets, 51-23 in the third quarter. The 51 points were also a team playoff record and tied an NBA record.

“I thought defensively the way the team came out and responded to some first-half stuff that we needed to fix was a fantastic statement,” Sixers coach Brett Brown said.

The Sixers were a much more energized team in Game 2.

“I thought tonight it was fantastic,” Embiid said about the team energy. “That is the energy we need for this series and the playoffs.”

The big difference for the Sixers from the outset was the aggressiveness of point guard Ben Simmons. And his teammates followed his lead.

Simmons caught some serious flak from the fans for his comments about their booing in Game 1. In this game, he didn’t allow the crowd to warm up their booing vocal cords.

Unlike the first game, when he would drive near the basket and then kick out, Simmons was going all the way to the hoop for the most part.

Limited to nine points in the 111-102 opening loss, Simmons had 16 by halftime and finished with a triple-double, 18 points, 10 rebounds and 12 assists.

“I was just trying to be me," said Simmons said, who recorded his second postseason triple-double. “Be aggressive, find my guys, and play the game the right way.”

For the second game in a row, Embiid’s caddy, 7-foot-3 Boban Marjanovic, had a strong game. He scored 14 points in the first half when things were tight, and ended with 16.

This time, the Sixers didn’t need the 36 points they received from Jimmy Butler in the first game. He scored just seven, but before Game 2 said he was disappointed he had no assists in the opener. Butler had seven dimes on Monday.

Tobias Harris, limited to four points in Game 1, scored 19; and JJ Redick, who had five points in the opener, added 17.

Spencer Dinwiddie led the Nets with 19 points.

After a 3-for-25 nightmare from three-point range in the opener, the Sixers were 9-for-23 on Monday.

Now it is the Nets who have to regroup.

“This was very physical, a great experience for our guys to understand what playoff basketball is all about and this week we have to respond,” Atkinson said. “They dominated us in the paint and on the boards.”

The Sixers outscored the Nets in the paint, 62-48, and outrebounded them, 49-32.

Late in the first half, things started getting testy.

Embiid was assessed a Flagrant 1 foul with 35.6 seconds left in the second quarter. While making a spin move, his elbow caught Brooklyn’s Jarrett Allen in the face.

Embiid understood why he was assessed the Flagrant foul.

“I wasn’t surprised, I saw the replay and obviously it wasn’t intentional," Embiid said. “I got him pretty good and I am sorry about it.”

With 2.1 seconds left, the Nets’ Rodions Kurucs was assessed a Flagrant 1 foul for bumping Simmons, who fell to the ground.

Simmons made 1 of 2 free throws to give the Sixers their 65-64 lead at intermission. They then won the game with the third-quarter blitz.