The 76ers and their fans were kind of low-key on the final Sunday of the regular season.

But after the Sixers nearly blew a 19-point lead, they settled down and went on to accomplish a major milestone. JJ Redick finished with 18 points, Ben Simmons had 16 and Robert Covington produced a seventh double-double in a 109-97 victory over the Dallas Mavericks at Wells Fargo Center.

It was the Sixers' 50th win of the season, a first for the franchise since 2000-01 and 17th time overall.

But the Sixers did more than reach a single-season plateau.

The expected victory over the tanking Mavs (24-57) also extended their winning to streak to 14 games to tie the franchise single-season mark set from Dec. 21, 1982, to Jan. 21, 1983. They also secured a top-four seed and an opening-round home-court advantage in the playoffs.

The Sixers (50-30) are in third place in the Eastern Conference, a game ahead of the Cleveland Cavaliers, each with two contests remaining.

"This shows how far we've come with this season," said Simmons, whose squad was projected to win 41.5 games by Bovada of Las Vegas. "Everyone putting us lower than expected. I think we pushed through the times. We had a tough start with the teams we've played.

"I think we got better over time."

But their 50 wins and 14-game winning streak put them in good company. The 2000-01 squad advanced to the NBA Finals, losing to the Los Angeles Lakers, 4-1.  The 1982-83 team won the league title, sweeping the Lakers, 4-0.

On Sunday afternoon, the Sixers built a 55-36 lead on Redick's three-pointers with 3 minutes, 29 seconds before intermission. However, the Mavericks pulled within four points (80-76) with 1:10 left in the third quarter. But the Sixers responded with a 9-0 run to take a 13-point cushion. The home squad appeared a little hungover from Friday's 132-130 victory over the Cavs (49-31).

"It's part of the rhythm beat of an NBA sort of schedule," said coach Brett Brown, whose squad is 20 games above .500 for the first time since 2000-01. "We came in after a big game. We wanted to play better than we did. We didn't feel like we played our best basketball."

The Sixers coach, however, made a point to give Dallas and its coach, Rick Carlisle, a lot of credit. Brown commended Carlisle for continuing to have his team play hard amid a struggling season.

"That's the understory,"  Brown said. "The other story is we won 50 games, we're on a 14-game winning streak, and we secured home court."

Simmons has been playing at an all-star level during the streak, averaging 14.7 points, 10.1 rebounds and 10.9 assists.  In addition to his 16 points on 7 for 10 shooting against Dallas, Simmons had seven rebounds, nine assists, four steals, one block, and three turnovers.

Meanwhile, Robert Covington had 15 points, 10 rebounds, three assists, two steals and two blocks. Reserves Marco Belinelli (15 points) and Ersan Ilyasova (11 points, 12 rebounds) were the other double-digit scores. Markelle Fultz, the backup point guard, finished with eight points on 4 for 8 shooting to go with three assists and two turnovers.

Brown acknowledged before the game that T.J. McConnell's playing time would take a hit with Fultz back in the rotation. He didn't lie. McConnell was only on the court for the final 2:24 for mop-up duty in a blowout win.

"I'm not going to cry over spilled milk," McConnell said. "Markelle and Ben are special players, and they need to be out there for us to win.

"I just got to stay ready. If my number's called, I've just got to go out there and be a pro and help this team."

Sunday marked the Sixers' sixth straight game without Joel Embiid. The all-star center fractured his orbital bone near his left eye on March 28. He had surgery on March 31. At that point, the normal recovery timeline was two to four weeks. The Sixers, however, did not give a timeline.

Very few people — if anyone — expected the Sixers to win 50 games this season. How could they?

There were too many unknowns for the team that won a combined 75 games over the previous four seasons.

Two of the season's biggest question marks centered on Embiid's health and Simmons' ability to play point guard.

Embiid, who had season-ending left knee surgery last season, wasn't in shape at the start of this campaign and wasn't cleared to play in back-to-backs until February. Meanwhile, folks wondered whether Simmons, who played point forward at LSU, could guard his position and be effective offensively despite shying away from shooting long-range shots.

But while Embiid got in shape and Simmons proved himself, the Sixers had to deal with the Fultz ordeal.  The first overall pick in June's draft missed 68 straight games from Oct. 25 to March 26 with the yips.

Yet, he's back and making an impact.

But while Fultz remained sidelined, Simmons learned the position and Embiid got healthy, the Sixers had to learn how to stop losing games in which they held large leads. And there was the brief adjustment period that came with free-agent acquisitions Belinelli (in February) and Ilyasova (in March). They provide a lot of spark off the bench.

The Sixers overcame a lot of things this season en route to becoming the hottest team heading into the postseason.

"If you said did you know that we're going to have the second-best record in the NBA after Christmas, the fifth-best record for the whole year, and [two] games way from securing … a third seed in the East, you'd be pretty pleased with those results," said Brown, whose squad is 36-12 after Christmas.

The Houston Rockets hold the league's best record since then, at 39-10.

The Mavericks were without the services of Jose Barea (left rib muscle strain), Seth Curry (left leg surgery), Wesley Matthews (right proximal fibula fracture), former Sixer Nerlens Noel (league suspension) and  Dirk Nowitzki (left ankle surgery).