"Hernandez was outstanding," Sandberg said.
"Today was his day," Ben Revere said. "It was good."
The Phillies have won three of their last four series - the lone loss was a shortened one-game meeting with New York - and are 15-14. The reason is their pitching; Phillies starters have a 2.65 ERA in their last 11 games. They have allowed two runs or fewer in eight of those 11 starts.
The maligned bullpen held, too. Both Mike Adams and Antonio Bastardo pitched for the third time in three days to preserve the lead. Denard Span singled off Hernandez to start the eighth. A bunt moved Span to second, and Sandberg opted for Adams. He coaxed Jayson Werth into a weak groundout.
Bastardo did not make his escape simple. He entered to face a lefty, Adam LaRoche, but walked him on five pitches. That meant Anthony Rendon, a .481 hitter against lefties this season, batted with the tying run 90 feet from home.
Rendon flailed at the first pitch, a 92-m.p.h. fastball. He took another outside fastball for strike two. Two Bastardo pitches missed low. The fifth, a 93-m.p.h. fastball, caught enough of the plate. Home-plate umpire Sean Barber made an emphatic strike three call as Carlos Ruiz pumped his fist.
Zach Walters blasted two Jonathan Papelbon pitches foul - with help from winds that gusted to right - and struck out to end the game.
"That's what our bullpen is capable of doing," Adams said. "Hopefully we can get this thing turned around and start going in the right direction."
Hernandez reversed his recent problems with a sterling start. He was not informed until Saturday afternoon that his Tuesday start was bumped to Sunday.
"It's not that big a deal," Hernandez said. "You have to do what you had to do."
He pitched once as a reliever but spent most of his downtime with side work in the bullpen. The Phillies paid $4.5 million for Hernandez because they viewed his ground-ball-inducing sinker as a commodity. He recorded 11 groundouts Sunday and struck out three.
Hernandez threw more balls than strikes in the first inning. Washington twice walked but Kevin Frandsen erased himself when he tried to go from first to third on a ball hit to left field that nicked third baseman Jayson Nix's glove. John Mayberry Jr. threw out Frandsen.
Hernandez settled down. He retired 12 of the last 13 batters he saw.
"He attacked the hitters," Sandberg said. "He was ahead in the count. He used all of his pitches. He was really effective."
The Phillies scored in the first inning for the third time in three games. Jimmy Rollins smashed a triple to left-center. Chase Utley followed with a single through the middle, and Nationals lefty Gio Gonzalez trailed just 11 pitches into his outing. Washington has allowed 32 first-inning runs - the most by any team - in 31 games.
It was all Hernandez and the Phillies bullpen required for the team's fifth shutout win in 29 games.
BY THE NUMBERS
Roberto Hernandez's ERA in his last three starts before Sunday.
Shutouts by the Phillies this season.
Consecutive scoreless appearances by Jonathan Papelbon.