Tuch extended it to 2-0 at 12:37 of the second period after taking a backhand pass from Jokiharju above the slot and scoring on a wrist shot.
McMichael cut it to 2-1 at 14:36, directing a backhand pass from Max Pacioretty in front past Luukkonen’s blocker.
Jack Quinn made it 3-1 at 9:46 of the third period by scoring glove side from the high slot.
Dylan Cozens extended it to 4-1 at 17:43 with an empty-net goal.
Wilson tipped Carlson’s shot with Lindgren pulled for the extra attacker at 19:00 for the 4-2 final.
“This has been the way our team has gone all year,” Washington coach Spencer Carbery said. “And if we get a couple goals there, and now we'll protect our lead. If we don't and we trail, now it becomes a challenge. And that's what you saw tonight.
“And there was a few, like you saw some of the young mistakes from our group in this situation where some nerves come in. … This time of year, that just can't happen. You have to be able to execute a simple chip out off the wall. … But for the most part, I thought there was enough positivity to win the game. We just weren't able to finish and were trailing in that game.”
NOTES: Washington forward Alex Ovechkin had an assist on Wilson’s goal, giving him 697 in his career to pass Sergei Fedorov for the second-most by a Russian-born player in NHL history. … Carlson reached 50 points in a season for the sixth time in his career, moving him past Scott Stevens for the most 50-point seasons by a defenseman in Capitals history. … Benson is the third Sabres player to score at least 10 goals in a season at the age of 18, joining Phil Housley (17 in 1982-83) and Pierre Turgeon (14 in 1987-88).