WASHINGTON, D.C. -- For at least one day, the Philadelphia Phillies had a lockdown bullpen.
But for another day the bullpen was questionable for the Nationals.
Hector Neris pitched a scoreless eighth for the Phillies and Joaquin Benoit threw a perfect ninth for his first save of the season and the team's second.
Benoit had one save last year and two in 2015, although he did save 24 games for the Detroit Tigers in 2013.
"He did a real good job," Phillies manager Pete Mackanin said of Benoit. "He is a 14-year veteran. He is not scared."
Blanton came on in the eighth and hit the first batter, Freddy Galvis, with a pitch. After retiring pinch hitter Brock Stassi, Blanton (0-2) yielded the home run to right field by Hernandez, who had a walk-off single last Sunday to beat Washington and added two hits Saturday.
"I am trying to see more pitches (as a leadoff hitter)," Hernandez said. "That is my job. I am happy. We needed a win."
Mackanin said of Hernandez: "I can't say enough about Cesar. He has been playing hard. He laid down a bunt for a hit (in the fourth). He didn't bunt for a hit that time (with the homer). He is turning into a really good Major League player."
Washington pitchers have allowed 12 homers this year -- 10 by relievers. Blanton has given up three homers in seven innings.
"There's no explanation," Nationals manager Dusty Baker said of his bullpen. "It's been almost everyone."
Other Washington relievers who have given up homers this season are Shawn Kelley (three), Oliver Perez (one), Enny Romero (one), Sammy Solis (one) and Blake Treinen (one).
"Granted, it's still early," Washington starter Tanner Roark said of the bullpen. "They'll be fine. We're not worried about them at all. We believe in them. That's us."
Chris Heisey, in his first start of the season for the Nationals, lined a solo homer to left off Phillies starter and winner Jeremy Hellickson (2-0) to tie the game, 2-2, in the seventh. It was the first hit of the season for Heisey in six at-bats.
"Well, he works hard," Baker said of Heisey, who grew up about 90 miles west of Philadelphia. "He works hard at it. That's why we play him (in spots)."
The Phillies took a 2-1 lead in the fourth when Odubel Herrera hit an RBI double and eventually scored on Maikel Franco's run-scoring groundout.
Anthony Rendon hit a two-out RBI single to left to give the Nationals a 1-0 lead in the third. His hit scored Jose Lobaton, who walked with one out and went to second on a single to right by Roark.
Roark was hit on the left (non-throwing) forearm on a comebacker by Galvis in the fifth. The ball deflected to third baseman Rendon, who threw out Galvis, and Roark stayed in the game.
Roark doubled in his next at-bat in the fifth for his second hit of the day. He went seven innings and gave up two runs on four hits and did not figure in the decision.
Hellickson lived on the edge most of the afternoon, giving up several line drive outs and retiring Michael A. Taylor and Lobaton on long flyballs in the fifth. The right-hander was aided by good players from shortstop Galvis and others.
"It is fun to watch him play," Mackanin said Galvis. "(Howie) Kendrick made two nice plays (in left). When a line drive is hit right at you, they are the hardest plays to make."
Bryce Harper flew out to the warning track in the sixth against Hellickson, who left his last start on Sunday because of a cramp in his right arm after throwing five scoreless innings against the Nationals.
Hellickson yielded four hits and two runs, as he relied on a steady diet of off-speed pitches.
"He was really good," Mackanin said of Hellickson. "It makes it a lot easier for us (with seven innings). "He just knows how to pitch. He made a few mistakes. Overall, that is just the way he pitches."
NOTES: To celebrate Jackie Robinson Day and Black Heritage Day, the Nationals' guests included Troy Hylick and Michael Moore, grandsons of West Virginia native Katherine Johnson. She was portrayed in the recent movie "Hidden Figures." Robinson made his Major League debut for the Brooklyn Dodgers on April 15, 1947. ... Washington CF Michael A. Taylor made his first start of the year and C Jose Lobaton made his second. ... Phillies RHP Jerad Eickhoff (0-1, 2.63) will face Washington LHP Gio Gonzalez (1-0, 0.69) in the series finale Sunday. ... Washington pitching coach Mike Maddux was 10-13 with a 4.51 ERA with the Phillies from 1986-89.