Game 2 is Wednesday night at Indiana.
The Pacers have lost both of their playoff series' openers and will face another uphill battle — just days after rallying from a 3-2 deficit to beat Atlanta in seven games in the first round.
Washington made a playoff franchise-record 10 3-pointers, going 10 of 16. Ariza was 6 for 6 with five coming in the first half when he scored a playoff-career best 17 points.
But the Wizards won this one because of their defense, especially late.
After pulling out to a 92-78 lead midway through the fourth quarter, Indiana scored six straight to close to 92-84 with 3:24 left.
But Washington didn't allow another field goal for nearly six minutes — from 7:41 left in the fourth until Indiana's last-minute three-point flurry, and by then it was too late.
The Wizards took advantage of a five-day break after beating Chicago in the first round, looking fresh and stealing a page out of the Hawks' playbook by spreading out the Pacers.
It worked perfectly.
The Wizards jumped to an 8-0 lead and extended the margin to 28-15 after one quarter.
The Pacers spent the second half playing catch-up and the Wizards never let them get closer than two possessions.
After the Wizards took a 68-52 lead midway through the third quarter, the Pacers finally charged back with a 10-0 run that got them within 68-62.
But Washington sealed the game with a 7-0 fourth-quarter run that made it 92-78 with 5:46 to play. It was too much to overcome for Indiana, which made four three-pointers in the final minute.