CLEVELAND — The Cavaliers’ return serve turned out to be rather fierce.

As is often the case in the playoffs, and standard in this year’s postseason, teams returning home get a big boost from their comfort and their crowd. Such was the case at Quicken Loans Arena on Saturday night, when the Cavaliers broke out of their teamwide slump to begin to fight back in their second round series against the Boston Celtics.

Using a huge first-quarter run to expel some of the offensive demons that besieged them earlier in the week on the road, the Cavaliers built a massive lead and then sat on it on their way to a 108-84 Game 3 victory.

In the second round of the playoffs, the lower seed in all four playoff series lost the first two games on the road and then came home and won. The Cavaliers solidly continued that trend and assured themselves a return trip to Boston.

LeBron James continued to struggle offensively against the Celtics’ collective system to stop him, but this time his help showed up and it made quite a difference. Perhaps the biggest impact came from Ben Wallace, who surprised his teammates and coaches by arriving at the arena with the intention to play despite suffering from allergies and an inner-ear infection that caused continued dizziness.

Wallace didn’t take part in the morning shootaround and it wasn’t clear up until tipoff whether his head would be clear enough to take the floor. When he did, he made up for lost time with a furious stream of energy that fueled the sellout crowd and his teammates.

Wallace chased down several key loose balls, played strong defense and got two early baskets that shook the Cavaliers from their doldrums. He finished with nine points, nine rebounds, two blocks, two drawn charges and one fourth-quarter standing ovation.

“He’s been like that for us throughout the playoffs,” Cavaliers coach Mike Brown said. “He’s able to impact the game without scoring.”

After shooting just 34 percent as a team and falling into an ineffective and rote offense in Games 1 and 2, the ball started flying around the floor from the first quarter on.

The result was open shots, shots that actually started falling. With each one that went down from different players the momentum started to build and the Cavaliers got their teeth back. By the end of a 27-4 run, the usually defensive juggernaut Celtics were dazed and never recovered.

The Cavaliers had 11 assists in the first quarter and 19 in the first half, when their lead swelled to as much as 26 points, as they shot 66 percent. For the game, the Cavaliers shot 54 percent and piled up 29 assists.

The Celtics played the same defense as they had in the first two games, especially against James, walling off the paint with multiple bodies. James again mostly took jump shots and mostly missed them. He shot just 5-of-16 for 21 points and is still a miserable 13-of-58 (22 percent) shooting in the series. Though he contributed with eight assists, three blocks and four steals. He also absorbed his fourth flagrant foul of the postseason when Celtics forward James Posey collared him on a drive in the second quarter.

“I haven’t shot the ball as well as I liked, but the win is all that matters,” James said. “I do so much more than just shoot the ball, it was key other guys stepped up.”

With the ball moving more, the Celtics weren’t able to set up and remain in their quasi-zone in front of James. It was exactly the sort of action Cavaliers coach Mike Brown begged from his team in the off day between games, and he got it.

It also helped the cause that there were plenty of hot hands to go to, a luxury the Cavaliers simply didn’t have in Boston when only Zydrunas Ilgauskas seemed to be able to get in the correct spot to take an open shot, much less make one.