The Washington Mystics sacrificed for their win Wednesday night against the Dallas Wings.

Star forward Elena Delle Donne wore it on her chin, bandaged postgame after receiving three stitches after getting hit in the fourth quarter. Center Krystal Thomas wore it on her legs, each plastered with three ice bags each instead of the usual one as she sat in the locker room. Point guard Kristi Toliver told of it with her voice, uncharacteristically hoarse for the typically quiet leader.

The aches and pains were worth it as Washington defeated the Dallas Wings, 86-76, in a single-elimination playoff game in front of 6,482 at Capital One Arena to advance past the first round of the playoffs for the first time since 2002. Washington will play at New York on Sunday at 5 p.m. in the second round in another single-elimination game.

A physical bout that finally revealed glimpses of the Mystics’ full potential after struggling through a regular season wrought with injuries, Washington also notched its first home playoff win since 2004.

“When you are trying to build something, there are steps you have to take,” Coach and General Manager Mike Thibault said. “A game like this is another major step because, No. 1, we had to win a game in the playoffs to get to the next round. No. 2 is your team needs to figure out — we didn’t shoot the ball great, but we played great defense. I mean, we held them to [33.8] percent from the floor. And in general, playoff games are more physical, more things are allowed to happen, and if you can fight through that and still keep your defensive presence about you, it’s great.”

Thibault had delivered strict instructions to his team ahead of Wednesday’s game — no one was to overextend themselves. The Mystics (19-16) entered the postseason healthier than they had been since the end of July, when star forward and 2015 league MVP Delle Donne injured her left thumb, and with 11 of 12 players available.

Only Tayler Hill, who tore her right anterior cruciate ligament and was lost for the season in July, remained on the bench.

The Mystics looked more like the team those around the WNBA expected them to be at the beginning of the season. Their defense was sharp, and their three driving forces on offense played in harmony.

Delle Donne was outstanding in her Mystics playoff debut. She scored 25 points on 8-for-18 shooting, collected 11 rebounds and added three assists.

Emma Meesseman added 16 points, 10 rebounds and five assists and Toliver added 16 points. On the defensive end, center Krystal Thomas grabbed a team-high 17 rebounds and played a huge role in the Mystics’ 25 second-chance points compared with the Wings’ 15.

“Twenty offensive rebounds tells the story right there,” Dallas guard Skylar Diggins-Smith said. “They just hustled. I think Krystal ended up with, how many? Fifteen, 16, 17? That was the x-factor for them.”

The Mystics used lockdown defense and a 17-5 run to start the third quarter to push past Dallas, who they lost to twice in the regular season.

Washington lost a 13-point lead in the second quarter thanks in large part to a nine-point surge from Wings guard Aerial Powers, playing just her 13th game of 2017 after recovering from a hip injury that required surgery in the offseason, in the final three minutes of the first half.

The second-year pro led Dallas with 21 points on 6-for-15 scoring.

Washington held Diggins-Smith, the Wings’ leading scorer, to just 15 points, by far her lowest points total against Washington this season, and held second-leading scorer Glory Johnson to 15 points and 14 rebounds.

“We just know that we had to be aggressive against this team,” Meesseman said.

The Mystics not only weathered a chippy game — Delle Donne’s chin injury left blood on the court with less than three minutes left in the game, and Powers was ejected with 1:11 remaining — they also muscled through the bad habits that had haunted them all season.

Washington avoided stumbling late when the Wings cut the margin to four in the closing minutes. They committed 10 turnovers but outrebounded Dallas 52-42.

Toliver, who won the WNBA title with Los Angeles last year, called it a foundational victory.

“It was very important to me because I know what it feels like to make a deep run in the playoffs, and I want to have that feeling again,” she said. “. . . Those are the environments that you want to be in, and it’s fun. I want this team to have fun and to know what it feels like to make a run and play as hard as you can and see what happens.

“I don’t think very many people chose us to win, but I think we’re coming along. We’re believing in the system, and we’re believing in one another, and when you do that, anything’s possible.”