CHICAGO -- Nate Schierholtz thought he could put together a nice season if he found the right place to go when he was a free agent last winter.
He ended up in Chicago, and it's working out in a big way.
"I'm just trying to put up good at-bats and help the team out," Schierholtz said. "Just try not to do too much. Just trying to keep it simple and go out there and have fun."
Schierholtz connected for a three-run shot in the first and a two-run drive in the seventh in his fourth career multihomer game.
He also had an RBI double in the third in Chicago's highest-scoring game since a 14-6 victory over Houston on June 23.
He went 3-for-4 while moving into a tie with Anthony Rizzo for the team lead with 18 homers. He also is second only to Rizzo with 58 RBIs.
Not bad for a journeyman outfielder who was non-tendered by Philadelphia after last season and agreed to a one-year deal with Chicago in late December.
"I'd like to be part of the future here," said Schierholtz, who feared he might be traded before last month's non-waiver deadline. "I'm happy I'm not out of here."
It was more than enough for Samardzija (7-11), who pitched a six-hitter for his second complete game of the season and No. 3 for his career. He struck out five and walked none in his first victory in a month.
"Regardless of what I did out there, you've got to tip your hat to the offense," Samardzija said. "Puts you in the zone. Allows you to relax and throw your pitches. They were great out there."
Nationals right-hander Jordan Zimmermann (14-7) allowed a season-high eight runs in five innings in his first loss since July 26 against the New York Mets. The All-Star was 2-0 with a 1.59 ERA in his previous three starts.
"My stuff's been good all year," he said. "Fastball's been good, slider was good tonight. Just the location was off tonight, and it's something I've got to work on."
The three home runs matched a season high for Zimmermann, who is tied with St. Louis ace Adam Wainwright for the NL lead with 14 wins.
"He's a tremendous pitcher; he's going to be fine," Nationals manager Davey Johnson said. "This was not good, obviously. But I think he came through it all right."
The Nationals acquired outfielder David DeJesus in a pregame trade with the Cubs, but their fringe playoff hopes took a hit with their third loss in four games.
They trail NL East-leading Atlanta by 16 games, but the most important number at this point is their 10 1/2-game deficit compared to Cincinnati in the race for the second NL wild-card slot.
The acquisition of DeJesus gives Washington another veteran left-handed bat for its bench. The 33-year-old DeJesus hit .250 with six homers and 27 RBIs in 84 games with the Cubs, who began the day in last in the NL Central.
DeJesus hit for Ryan Zimmerman in the eighth and received a warm ovation from the crowd of 31,290 on a beautiful night in Chicago. He popped out to shortstop and remained in the game to play center field.
"I'm going to give it my all," said DeJesus, who merely had to move over to the visitors clubhouse at Wrigley Field to join to his new team. "Try and be a guy out there as a leader and a guy that young guys can learn from."
Despite the leadership and left-handed bat DeJesus can provide, a source told FoxSports.com that the Nationals have placed their new acquisition on revocable waivers.
The Cubs get a player to be named in the trade, but they also save about $2.5 million, including a $1.5 million buyout for a 2014 team option worth $6.5 million. General manager Jed Hoyer said the money was a "strong consideration."
"We really like David a lot," Hoyer said. "I've told his agent and Theo (Epstein) told David directly, we'd be willing to talk to him about bringing him back at some point. He's a good mentor for our younger guys."
Cubs 1B Rizzo (illness) got the day off. Manager Dale Sveum said he hopes he will be ready for Tuesday night's game. ... The Cubs activated OF Brian Bogusevic (strained left hamstring) from the 15-day disabled list to take DeJesus' roster spot, and Hoyer said OF Ryan Sweeney (broken left rib) likely will begin a rehab stint next week. ... The Nationals released OF Roger Bernadina to make room on their roster. Bernadina hit .178 in 85 games with Washington. ... Nationals RHP Dan Haren (7-11, 4.79 ERA) faces Cubs LHP Chris Rusin (2-2, 3.06 ERA) in the second game of the series.
Information from The Associated Press was used in this report.