What could have been a gamble turned into a relatively easy run, which was all the offense Miami needed to win for the eighth time in 10 games, while dealing another big blow to the Nationals' playoff chances.
Coupled with the Mets' win over the Braves, the Nationals are now 8 1/2 games out in the National League East.
Washington and Miami were even at 1 when Realmuto doubled off Casey Janssen to open the seventh inning. The catcher took third on Ichiro Suzuki's bunt. Janssen took a chance and tried to nab Realmuto at third, but the play allowed both runners to be safe.
With runners on the corners and no outs, Rojas swatted a sinking liner to right. According to Statcast™, the ball projected 234 feet from home plate with an exit velocity of 76 mph.
Harper dashed in and made a sliding catch.
"I wasn't running, until I saw Harper slide," Realmuto said. "I knew it was too shallow to run, until he slid. It's a tough play to make that throw home. He's an incredible athlete, but that's a really hard play. I figured I'd take my chances with him."
Harper's throw was up the line, and Realmuto crossed the plate without a serious challenge.
"I tried to get soft contact on Rojas and he hit it potentially just a little too soft where Harp had to slide for it," Janssen said.
Realmuto has showcased his plus-speed several times during Miami's homestand. He tagged and scored on Martin Prado's walk-off sacrifice fly to left against the Mets on Sunday.
He's also had a two-home run game, with one of the drives being an inside-the-park home run on Tuesday against the Brewers.
Miami manager Dan Jennings notes Realmuto's speed is rare for a catcher. Asked for a comparison, Jennings said maybe Craig Biggio, before he converted from catcher.
"That kind of speed," Jennings said. "Very few guys have that component. He can steal a base. He can go first-to-third. He had that inside-the-park [home run] the other day. He has the ability to go back and tag right there on a medium-depth fly ball and score a run. It's a tremendous weapon to have on the bases."