Boston, which won Game 5 at home by 22 points, led Game 6 by 69-66 entering the fourth quarter, when a relatively blah game became much more compelling.
The Cleveland Cavaliers' opponent for the 2017 Eastern Conference Finals will be decided Monday night.
For both the Celtics and the Wizards, the next round means a meeting with the defending NBA Champions, the Cleveland Cavaliers, which hasn't gone good for any team to face them in the last two years.
After the Wizards dominated the paint most of the series, it was the Celtics who outscored the Wizards 58-40 in the paint in Game 7. Olynyk broke out everything in his arsenal, including his seldom used low-post game to slip some nifty finger rolls by smaller defenders. Outside of Kelly Olynyk himself, probably not.
Keep this in mind, Celtics fans.
And then he began to talk about his native Canada, and how he viewed Game 7 as if he were playing for his national team and they needed to win one game in order to get to the Olympics. However, there were those three seconds left and the Wizards had to quickly regroup and try to lock in on defense to stop the Celtics and more specifically Isaiah Thomas from scoring.
While Thomas is anxious for the opportunity, one thing he says he won't be is nervous. In the War of the Kellys, Olynyk prevailed. No matter what anyone thinks about their chances in a potential series against LeBron James, the feat will still be a great one for this version of the Boston Celtics. It was an embarrassment coming off the bench. Scott Brooks might be a fine National Basketball Association coach, but you'd be advised to look away from his bench rotations. Five points - come on!
The NBA playoffs have been a favorite's delight so far.
Markieff Morris had 16 points and 11 rebounds for Washington.
Wall continued his trend of slow starts.
The Wizards Bradley Beal led all scorers with 38 points.
Leonard had 26 points and eight rebounds.
The Wizards hung tough, paced by Otto Porter Jr., and closed the gap to 46-45. Washington might as well have had been dealt a red card from the jump. The Wizards as a whole started 1 for 15 from beyond the arc. It could not be worse.
Wall's game-winner was treated as another example of his star power - Morris described it as the point guard putting the team, and the city, on his back. But we kept going and stayed the course and that was what this team has done all season long. Either way, Celtics win here and move onto the Eastern Conference Finals. Horford had been an All-Star with the Atlanta Hawks, but would disappear in huge moments while with Atlanta.
The 2015 MVP, who was acquired in an offseason trade with Chicago, played just 23 minutes as she dealt with foul trouble.
While he is talented enough to be the second-best player on a championship contender, he hasn't always shown that.
The prize the Celtics get for winning this Eastern Conference semifinals series?