Espinosa and LaRoche had two hits apiece. Hitting .129 after going 0 for 4 on May 1, LaRoche is seven of his last 13 with six walks.
Harper made it 3-1 when he hit Sanchez's first pitch over the wall in right- center with two outs in the fifth for his 10th home run.
"It was an 0-0 curveball, a pitch he hadn't seen yet in the game, and it was a good 0-0 pitch," Tiger catcher Alex Avila said. "A lot of guys just take that pitch, or if they do swing, they don't hit it out of the park normally. That was pretty impressive."
Zimmermann's scoreless inning streak, which matched a career high, ended in the third. With two outs, Hunter doubled down the third base line and Cabrera followed with a sharp single between third and short to make it 1-0.
"The plan tonight was not to let Fielder and Cabrera beat me and (Cabrera) got that ball through the hole," Zimmermann said. "He's a great hitter and you're going to give up hits like that once in a while."
Cabrera is hitting .688 (11 for 16) with runners in scoring position over his last 11 games.
Washington tied it in the bottom half when Span tripled and scored on Harper's sacrifice fly.
NOTES: Cabrera appeared to grab his right hip after grounding out in the sixth. "My back was tight, a little sore, my low back," he said. "But no big deal. I was able to play nine innings, so, hopefully tomorrow, it will work out, regular stretch and ready to play." . Detroit's RHP Doug Fister (4-0, 2.48) and RHP Dan Haren (3-3, 5.01) will start Thursday's finale. . Washington RF Jayson Werth (strained right hamstring) missed his fourth straight game and will have an MRI on his hamstring Thursday. Johnson said Werth, who has had muscle spasms, has a stomach virus which is causing dehydration. "I have a good feeling if they can get rid of the bug, he'll be all right," Johnson said. . Managers Johnson and Jim Leyland were meeting for the first time since Sept. 19, 1999, when Johnson's Dodgers defeated Leyland's Rockies, 5-2. ... Carol Anderson, wife of the late Hall of Fame manager of the Tigers and Reds, Sparky Anderson, passed away Tuesday night in her Thousand Oaks, Calif., home.