Indiana (8-9) has won two straight after losing five of six. The Fever shot 53 percent from the field and beat Washington for the second time in three meetings this season.
The Fever arrived in Washington early Wednesday morning after a 77-70 road victory over the Eastern Conference-leading Atlanta Dream on Tuesday night and went on to get back-to-back road wins for the first time since June 28-29, 2011.
"I thought we really showed a lot of heart," Indiana coach Lin Dunn said. "We're on a back-to-back, flew in this morning, had a tough game last night in Atlanta. I thought we matched their energy, their quickness. They wanted to push the ball and so did we."
The Fever fought through the fatigue.
"That's the one thing about being a professional athlete," Kizer said. "This is our schedule. This is our lives so we have to keep it going."
The Fever outscored the Mystics 31-14 in the second quarter, closing the first half with a 20-5 run to take a 42-29 lead. Lynetta Kizer scored all 10 of her points in the quarter as Indiana's reserves helped spark the rally after the starters fell behind 8-0.
"The group that I started out with, I don't know if they knew the game had started," Dunn said. "So I jerked them out, put some subs in and they took over and got us back in the game."
Monique Currie scored 18 points for the second straight game for the Mystics (7-11). All five starters scored in double figures, but Washington has lost two straight, both at home, and now faces five straight road games.
Indiana held Washington to 2-for-17 shooting on 3-point attempts, dropping the Mystics to 6 for 47 from beyond the arc over their last three games.
Currie asked to look at a box score before speaking with reporters. She immediately recognized the numbers that held her side back.
"Three-point percentage," said Currie, who missed four of five of 3-point tries. She also knew that there was more to the losing story.
"We didn't put together two good halves tonight," she continued. "The second quarter was really bad for us. They were the aggressors."
Washington rallied in the fourth quarter as Kia Vaughn's jumper cut Indiana's lead to 78-76 with 19 seconds remaining. The Fever made two free throws in the final 10.3 seconds.
"Our team is going to find out I'm a little more stubborn than they are," Mystics coach Mike Thibault said. "I want to play a certain way, I want to play at a faster pace and they don't understand what that pace is right now. ... The second half we decided to do that. I wish we played like that in the first half."