Toews scored three goals and had two assists for his sixth NHL hat trick and third five-point game. He has 16 points (five goals, 11 assists) in his past 12 games.
"It gives our team confidence when you see goals go in," Toews said. "We played the way we played [today] in front of our fans, we hear the horn and the fans responding. It's nice to play an exciting game in front of them and get a little something to cheer for."
Kane had two goals and three assists. He has 20 points (seven goals, 13 assists) in an eight-game point streak.
"Yeah it was a fun game. Kind of like a playoff-type atmosphere, playoff-type game," said Kane, who is two points from 900 in the NHL. "It was back and forth, it seemed like no matter how big our lead, we couldn't make it big enough to feel comfortable. Overall I think it was a good win for us."
[WATCH: All Capitals vs. Blackhawks highlights]
Dylan Strome had a goal and two assists for the Blackhawks (17-24-9), who ended a five-game losing streak. Collin Delia made 34 saves.
The Capitals (27-16-5), who have been outscored 23-9 during the losing streak, had not lost five straight games since Oct. 26-Nov. 4, 2014. Each of the five Washington goals was scored by a defenseman, including two by John Carlson.
Video: WSH@CHI: Carlson blasts one-timer past Delia
"There are enough areas where, some nights we clean up one thing and get worse at a couple of others," Carlson said. "Can't seem to find that consistent balance, and, for me, we haven't been great starting a lot of these games. Feels like we're down a man the first shift or give up the goal first shift, stuff like that."
Brooks Orpik, Dmitry Orlov and Matt Niskanen scored for the Capitals. Braden Holtby allowed four goals on 11 shots before being replaced by Pheonix Copley (14 saves) at 2:30 of the second period.
Brandon Saad gave the Blackhawks a 1-0 lead at 6:36 of the first period before Kane scored 1:20 later to make it 2-0 at 7:56.
Video: WSH@CHI: Kane scores to extend point streak
"Something that I take responsibility for, that first goal, if you make a save there, it changes the game around," Holtby said. "Little plays like that have a big effect, something that's on my shoulders."
Orpik scored to make it 2-1 at 14:25 of the first.
Toews scored 28 seconds later to give Chicago a 3-1 lead at 14:53, getting a stick on the puck in front of the crease before Orlov put it in his own net.
Video: Enterprise Hat Trick: Toews nets three for Blackhawks
Chris Kunitz appeared to score for the Blackhawks at 16:34 of the first, but video review confirmed the on-ice call that the puck went in under the side of the net.
Alex DeBrincat made it 4-1 at 2:30 of the second period, scoring off a one-timer for his 25th goal of the season.
Orlov made it 4-2 at 15:24 of the second.
Carlson scored at 3:09 of the third period with a one-timer from the left face-off circle to make it 4-3.
Kane gave the Blackhawks a 5-3 lead 36 seconds later when he scored a power-play goal at 3:45. It was his Chicago-leading 29th goal.
Toews made it 6-3 at 7:20, keeping the puck on a 2-on-1 and scoring from the right face-off circle.
Video: WSH@CHI: Toews nets second goal as Kane passes Wilson
Carlson's second of the game made it 6-4 at 10:38, and Niskanen got Washington within 6-5 at 13:55 with a shot from the right face-off circle.
Toews scored his third of the game to make it 7-5 at 14:57.
Strome scored an empty-net goal at 18:11 for the 8-5 final.
They said it
"It's nice because sometimes you give up goals like that, teams are feeling it, they have the momentum. Things aren't looking so good, it's tough to protect a one-goal lead when you got that much time on the clock. I think we did a good job of trying to turn it around and keep that momentum in the third period." -- Blackhawks captain Jonathan Toews
"It's a tough time right now, we just have to get over it, get a win. Doesn't matter how we play, where we play. Just have to get a win." -- Capitals captain Alex Ovechkin
Need to know
Kane has 12 goals in his past 11 games and six multipoint games in his past seven. It was his second five-point game in the NHL (Jan. 9, 2018, against the Ottawa Senators). … DeBrincat has seven goals in his past seven games. … Strome has five points (one goal, four assists) in his past three games. … Capitals forward T.J. Oshie had two assists and has seven points (three goals, four assists) in his past seven games.
Capitals: Host the San Jose Sharks on Tuesday (7 p.m. ET; ESPN +, SNE, SNO, SNP, TVAS, NBCSWA, NBCSCA, NHL.TV)
Blackhawks: Host the New York Islanders on Tuesday (8:30 p.m. ET; WGN, MSG+, NHL.TV)
Video: Toews' sixth hatty powers Blackhawks past Capitals