The 76ers are relying on their defense, which has been solid but has shown some cracks at times. On Saturday, in Jimmy Butler’s return against his most recent former team, the Sixers picked an opportune time to be at their defensive best.

Not only did they allow a season low in points in their 113-86 win over the visiting Miami Heat, but their performance was even better than the statistics indicated. Miami scored just 35 points in the first half. The Heat’s best quarter was the fourth when they scored 27 points, after the game had long been decided and all five starters were resting up for Monday’s key matchup in Toronto.

“Their defense really gave us some challenges,” Miami coach Erik Spoelstra said. “We struggled to get clean looks and you have to credit them, especially their length, on how they really protected the paint and forced us into some pretty rough possessions.”

Even Butler grudgingly gave the Sixers some praise.

“They have so many guys that can switch and do so many things well,” he said.

Entering Sunday’s games, the Sixers were eighth in the NBA in scoring defense, allowing 105.1 points per game.

Considering the opposition -- Miami has an 11-4 record -- it may have been the Sixers’ best defensive effort since an opening 107-93 home win over the Boston Celtics.

“When we’re all locked in defensively, our offense is just easy,” point guard Ben Simmons said. “Everything flows, we find each other and just play with a good pace.”

There are still issues to work out offensively, especially spacing on the court, but the Sixers (11-5) understand that the defense can bail them out. Against Miami, the Sixers shot 14-of-29 from three-point range (48.3%) and 50.6% overall.

“The defensive performance [was better] because I thought it was educated on what we were trying to get done,” Sixers coach Brett Brown said. “They are just an incredibly dangerous scoring team with the three-point shot and I thought that we tried to do some things defensively related to that.”

The Heat entered the game shooting 39.7% from three-point range, but hit just 6 of 24 (25%), including 1-for-12 in the first half when they trailed by 20 points.

“Defensively, [the Sixers] understand this city,” Brown said. “Whatever we do, it has to be blue collar and it’s got to be defense. The other stuff will happen from that base.”

While 6-foot-9 Al Horford and 7-2 Joel Embiid make it difficult inside, the Sixers backcourt tandem of the 6-10 Simmons and 6-5 Josh Richardson form an imposing defensive duo. It’s not a coincidence that the Sixers had such a strong defensive game with the return of Richardson, who missed the previous two games with right hip flexor tightness.

“They took us out of our offense a little bit tonight,” said Heat shooting guard Tyler Herro, among the better rookies this season. “That definitely made it harder for us, especially on our guards.”

The defense will get tested when the Sixers, who have won four in a row, return to the place of their playoff exit when they visit the Raptors on Monday. While the narrative will go back to the Sixers’ 92-90 Game 7 loss to the Raptors in the Eastern Conference semifinals that ended their season, the fact is that both teams are much different this season.

Still, the Raptors are 11-4 and have won three in a row. Entering Sunday’s games, Toronto was seventh in the NBA in scoring, averaging 113.7 points per game. Pascal Siakam leads the Raptors at 25.7 points per game.

Injury news

Furkan Korkmaz, who missed Saturday’s game with a left ankle sprain, is questionable for Monday’s game. He is expected to participate in the shootaround and will be re-evaluated afterward.

Kyle O’Quinn is questionable with a left calf strain that he sustained in Saturday’s game.

With Korkmaz and O’Quinn hobbling, the Sixers have recalled Jonah Bolden and Zhaire Smith from the Delaware Blue Coats and the two accompanied the team to Toronto.

Kyle Lowry (Cardinal Dougherty, Villanova) remains out for Toronto with a left thumb fracture. Also out are Stanley Johnson (groin), Patrick McCaw (left knee surgery), and Dewan Hernandez (right thumb sprain). Serge Ibaka (right ankle sprain) is doubtful.