Marcin Gortat (17 points, 12 rebounds) and the Wizards finally solve the Pacers after being routed in their previous two meetings this season. (Jonathan Newton/The Washington Post)

The Washington Wizards wanted to run Friday night at Verizon Center — away from a slump that included four losses in five games, toward their first playoff appearance in six years and past a slow-paced Indiana team that was the only Eastern Conference team that Washington had yet to beat this season.

Ultimately, the Wizards achieved their desired result, notching a 91-78 victory to avenge two blowout losses at the hands of the Pacers and extending their lead for the East’s sixth seed to 21 / 2 games. But the win was less because of their up-tempo play and more a result of the physical prowess of Marcin Gortat in the paint and the craftiness off the bench of 16-year veteran Al Harrington.

Gortat finished with 17 points and 12 rebounds and Harrington scored 10 of his 12 points in the second quarter to spark the Wizards, who never trailed against East-leading Indiana (52-21).

Though the Pacers are the NBA’s best defensive team, having held its previous five opponents under 90 points, it was Washington that turned up the defensive intensity, forcing the Pacers into 17 turnovers and 2-for-13 shooting from behind the three-point line.

“We just knew how big of a game this was for us, and we haven’t been playing well the last six or seven games,” said Wizards guard John Wall, who finished with 20 points. “The only way we can win games and finish out teams is by playing defense, and that’s what we did tonight.”

Indiana shot just 8 for 23 in the first quarter and committed seven turnovers, giving the Wizards opportunities to push the tempo off missed baskets. At times, they found success, such as the three-point play Gortat converted on a strong dunk. Other times, the Pacers’ big bodies cut off the lanes to the basket.

It wasn’t until Harrington, Drew Gooden and Andre Miller — affectionately known to Wizards Coach Randy Wittman as the “AARP Group” — entered the game in the second quarter that the Wizards were able to counter Indiana’s deliberate pace.

Ten straight points by Harrington, including a three-point play after a long pass from Miller, sparked a 15-2 run that gave Washington a 41-25 lead midway through the second quarter.

Though Paul George scored 19 points, he needed 22 attempts to get there as Trevor Ariza and Harrington shadowed him closely. And after being outmuscled in their first two meetings, Gortat stood strong in the paint against Indiana’s Roy Hibbert, holding him to just eight points and two rebounds.

“I feel like there’s a lot of pressure on me and responsibilities on me,” Gortat said. “I’ve got to be the big man who controls the paint and protects the rim.”

After the teams traded baskets for most of the third quarter, Harrington again entered the lineup to spark the Wizards (37-35). As the shot clock wound down, Harrington gathered a pass while cutting along the baseline before swinging the ball to Ariza, who knocked down his first three of the night. Martell Webster continued to stretch the Indiana defense by picking up a loose ball and draining his third three-pointer, extending Washington’s lead to 77-56 early in the fourth quarter.

Lance Stephenson kept Indiana in contention late, hustling on both ends of the floor to put together a 13-point, 14-rebound outing and help the Pacers pull within 10 late in the game. But Gortat again shut the door on Indiana’s chances, gathering a pass from Wall while rolling to the basket for a thunderous jam that sealed another Wizards win against a strong playoff contender.

“I don’t so much stress wanting to finish in the top six [in the East]. I want us to finish playing like this,” Wittman said. “I want to focus on playing like we did tonight and let the chips fall where they may.”