Tuesday night, Morgan received a one-out walk in the 10th, and pinch-hiter Alberto Gonzalez also walked. Adam Kennedy then hit into a force play at second and Morgan turned third and sprinted for home.
The throw there was high from Hanley Ramirez, and Morgan crashed into Hayes, who said later he "didn't have a chance to get my legs under me."
Yet Hayes, knocked to the ground and appearing stunned, held onto the ball for the out.
The catcher left the game with an injured left shoulder. He is scheduled to have an MRI on Wednesday and is expected to be out for awhile. And he's mad.
"Obviously his track record doesn't help himself," Hayes said. "Somebody who does that is looking to hurt somebody."
Added third baseman Chad Tracy: "It fires you up when you see the way he's been playing the last week or so."
Morgan, talking calmly afterward, said he thought the Marlins would try to turn a double play on Kennedy's grounder. As he turned third, he said he "peeked over" and saw Ramirez throwing to the plate.
"That's why I had to kick it up another notch," Morgan said. "I think if I tried to slide there, I probably would have hurt myself."
Asked to comment on the play after watching it several times on television, Nats manager Jim Riggleman said hindsight is 20/20 and it's hard to second-guess a split decision like that.
"I don't have any problem with his decision," the manager said.
The controversy could spill over into Wednesday night's game.
The ending overshadowed a stellar performance by Jordan Zimmermann. The 23-year-old right-hander showed why he was named the Nats' 2008 Minor League Pitcher of the Year, though he was long gone by the time the game was decided.
Zimmermann, coming back from Tommy John surgery, allowed just one baserunner over six innings -- a double by Gaby Sanchez in the second -- but left with the game scoreless.
"He threw quality strikes," Riggleman said, "and mixed up his pitches well."
Zimmermann, who lasted four innings and gave up five runs against the Cardinals in his first game back from Tommy John surgery, struck out a career-high nine and received good defensive support.
After Sanchez's double in the second, Tracy flew out to left. With Sanchez trying to take third, left fielder Roger Bernadina threw him out.
Then Kennedy made a nice play at second base on a hard-hit grounder by Mike Stanton.
Zimmermann coasted from there. He retired the last 14 batters he faced, eight of them by strikeout.
"It's probably the best I've felt in a long time," Zimmermann said. "I kept the ball down and actually got some fastballs inside, which I didn't do in my first start."
Zimmermann left after throwing 86 pitches, 55 for strikes. He said he could have thrown another inning, but the idea was to keep his pitch count down this soon after the surgery to try to avoid any recurrence of arm trouble.
Meanwhile, the Nats had trouble with Anibal Sanchez, the Marlins' right-hander who came in with a 3.29 ERA and lowered it to 3.14. He pitched seven shutout innings, allowing three hits.
The Nats threatened Sanchez just once. With one out in the third, Adam Dunn walked and Michael Morse singled. But then Ivan Rodriguez struck out and Morgan grounded out to second base.
With Sanchez gone, pinch-hitter Willie Harris singled with one out in the eighth, then went to second on Kennedy's groundout. However, Ian Desmond ended the inning with a grounder to third.
The game-winning run scored with two outs in the 10th when Ramirez slid under Rodriguez's tag after a throw from Bernadina. Rodriguez thought he should have been called out and vehemently protested to home-plate umpire Jim Wolf.
But after looking at replays, Rodriguez saw Ramirez had slid under the tag and apologized to Wolf.
Morgan found himself dealing with a controversy of his own, but he recognized that Zimmermann gave the Nats a huge lift on this night, especially with the news that phenom Stephen Strasburg is having Tommy John surgery Friday.
"He was fabulous," Morgan said. "He kept their hitters off-balance. It's nice to see the kid come up and pitch like that."