Daniel Murphy homered twice and had five RBIs, Adam Lind and Jose Lobaton hit two-run homers, and Anthony Rendon added a solo shot to lift the Nationals to a 14-4 victory over the Cincinnati Reds at Great American Ball Park.
"If you're on my team, everybody plays," Nationals manager Dusty Baker said. "We expect them to do the job. We had a big offensive production today. Had some home runs in a home-run park."
Washington (55-36) scored more than 10 runs for the 17th time this season to maintain its 9 1/2-game lead in the National League East over second-place Atlanta.
The Nationals played 28 of 30 days heading into the All-Star break and say they've benefited from the rest.
"We played a lot of baseball heading into the break," Murphy said. "I think we appreciated the rest. We're playing with a lot of energy."
The Nationals have outscored the Reds 29-11 in the first three games of the series.
"These games are going to happen but not with this frequency," Reds manager Bryan Price said. "It's deflating, but it doesn't mean we'll deflate. They did a lot of things right. We did a lot of things wrong."
Rendon, who had two home runs including a grand slam and six RBIs on Saturday, hit his 19th home run in the seventh inning off former Nationals pitcher Drew Storen. Lobaton also homered off Storen in the seventh.
Tanner Roark (7-6) allowed three unearned runs and four hits in six innings to snap his four-game losing streak.
"My two-seamer was moving," Roark said. "Felt like I could throw any pitch any time. I was able to relax, get some confidence and go right at them."
Before making his season debut on June 24, Reds right-hander Homer Bailey had made just eight starts the past two years because of multiple elbow surgeries. He allowed 14 earned runs in his first 4 2/3 innings back but gave up just one run through 6 2/3 innings in his last start at Arizona.
However, Sunday was a step back for Bailey.
With two outs in the first inning, Murphy hit his 15th home run of the season, a two-run shot off Bailey to give the Nationals a 2-0 lead.
Murphy then doubled leading off the second and scored on Chris Heisey's double to make the score 3-0.
"It's a testament to our offense grinding out at-bats," Murphy said. "I felt like we didn't give away a lot of pitches."
Two defensive miscues led to two Cincinnati runs in the third inning.
Bailey appeared to strike out swinging to begin the inning but reached first when Lobaton didn't throw to first assuming he'd caught the low pitch cleanly before it hit the dirt. The Reds loaded the bases and scored runs on a groundout and fielding error to cut the Nationals' deficit to 4-2.
Bailey then walked two to begin the fifth and Murphy launched his 1-2 pitch on to the bullpen netting in right field. It was his fourth multi-home run game but the first this season.
Lind's two-run homer later in the fifth, his seventh of the season off Ariel Hernandez, made the score 9-2.
Bailey (2-3) allowed eight earned runs and eight hits in four-plus innings.
"We lost this game because I didn't pitch well," Bailey said. "No excuses. I need to be more consistent. I would throw a good pitch, then two bad ones. It's simple. If you make a bad pitch it is going to get hit."
NOTES: The Nationals acquired RHP Ryan Madson and LHP Sean Doolittle from the Oakland Athletics in exchange for RHP Blake Treinen, LHP Jesus Luzardo, and INF Sheldon Neuse. ... Nationals 3B Anthony Rendon is the only major-leaguer to have multiple six-plus RBI games this season. He drove in six on Saturday night and 10 on April 30. Only two other Nationals players have had multiple six-RBI games in a season: Josh Willingham (2009) and Danny Espinosa (2016). ... Reds RF Jesse Winker made his first career start in the field and went 1-for-2 with two walks. His previous two starts were as a DH.