Zimmermann leaned his head back and winced. His first thought: "Double. No-doubt double."
"And then," the right-hander said later, "he comes out of nowhere and makes that catch."
Thanks to a dramatic, diving grab by little-used rookie Steven Souza Jr., who came on as a defensive replacement in the ninth inning, Zimmermann completed his gem, a 1-0 victory for the NL East champion Nationals over the Miami Marlins.
"I thought there was no way this would ever happen. My career numbers are something like one hit per inning, so I figure if I can make it out of the first, the hit's coming in the second," said the 28-year-old Zimmermann, a quiet guy who was a second-round draft pick in 2007 out of Division III University of Wisconsin-Stevens Point. "But today was one of those special days."
Almost morphed into a one-hitter, though. With two outs in the ninth and a 2-1 count, Marlins leadoff man Christian Yelich turned on a 94 mph fastball over the plate.
Souza was shaded well over toward the left-field line at a coach's prompting.
"He probably couldn't have been more out of position," said right fielder Jayson Werth, who watched it all unfold from what became a nearly silent home dugout.
"I was just thinking to myself, `It is not optimal to be Steven Souza right now, because as soon as you come into the game, every time, the ball's going to find you," Werth said. "I had a feeling something crazy would happen. But not that crazy, that's for sure."
Souza sprinted, extended his glove and leaped for the sensational catch, using his bare hand to squeeze the ball in his mitt as he fell.
"The one thing on my mind is, no matter how I'm going to get there, I'm going to get there," Souza said. "Getting there, I kind of blacked out."
Souza held his glove aloft to show he had the ball. Zimmermann raised both arms. Nationals relievers in the home bullpen lifted their arms, too. So did thousands in the Nationals Park crowd of 35,085, who roared with every pitch late.
"I don't think anyone in the stadium expected Souza to get to that," Zimmermann said.
Indeed, Miami's Mike Dunn said he and other relievers in the left-field visitors' bullpen started cheering as the ball headed their way.
"When he caught it," Dunn said, "it was just like, `Really? Did that just happen?"
Said Yelich: "With that on the line, that might be one of the best plays I've ever seen. Ever."
Souza jogged in and Zimmermann greeted him with a hug. Souza handed over the baseball, which Zimmermann shoved in his back pocket.
"It was too loud to hear everything he was saying," Souza said. "But I heard, 'I love you' and 'Thank you.'"
Souza's name now belongs alongside those of other players delivering superb catches to save no-hitters. The name that kept coming up in the Nationals' clubhouse was Dewayne Wise, the defensive replacement whose juggling, tumbling grab in the ninth saved Mark Buehrle's perfect game for the White Sox in 2009.
No major leaguer had thrown a no-hitter in Washington since Bobby Burke did it for the Senators in 1931 against Boston.
Quite a way to cap a regular season in which the Nationals finished with the NL's best record, 96-66. Washington hosts San Francisco or Pittsburgh in Game 1 of a division series Friday.
"Just an epic day for an epic season," said Denard Span, who set a Nationals season record with his 184th hit.
Zimmermann (14-5) struck out 10 and allowed only two baserunners. After retiring the first 14 batters, he walked Justin Bour on a low, full-count fastball with two outs in the fifth. In the seventh, Garrett Jones reached first base on a strike-three wild pitch; moments later, catcher Wilson Ramos picked him off.
Zimmermann's accuracy was unassailable: 79 strikes and 25 balls.
Starting on seven days' rest because his pitching shoulder got bruised by a line drive his last time out, Zimmermann poured in fastballs in the mid-90s mph, used his mid-80s slider to great effect and had his changeup fooling a Marlins lineup without NL home-run champion Giancarlo Stanton.
It was the fifth time there has been a no-hitter on the final day of the season. Happened last year, too, when Henderson Alvarez of the Marlins did it against Detroit. On Sunday, Alvarez (12-7) was Miami's starting pitcher against Zimmermann, allowing Ian Desmond's 24th homer for the only run.
With only a few clouds and the first-pitch temperature at 79 degrees, Zimmermann didn't need a whole lot of defensive help until Souza's memorable play. That might have been a good thing, because Nationals manager Matt Williams pulled his starters as the game went on.
"Three rockets, and right at guys," said Zimmermann, who had shaving cream in both ears from the on-field celebration. "That's when I knew there might be something special happening."
Frandsen wasn't so sure, saying: "Fifth inning's a little early to think, `He's got a no-hitter."
Maybe. But after the third, pitching coach Steve McCatty pulled Williams aside to point out that their initial plan to let Zimmermann have a light day's work with an eye to the postseason might not hold up.
"I said, `What do we do if we're going to give him six (innings) and he doesn't (allow) a hit?" McCatty recounted. "He just looked at me and said, `That's not funny.' I said, `Well, there's a good chance that's going to happen."
Thanks in part to Souza, it did.