Washington, DC (Sports Network) - Bryce Harper homered in his return, Jordan Zimmermann went six innings to earn his 12th win and the Washington Nationals upended the Milwaukee Brewers, 10-5, in the opener of a four-game series.
Harper had missed 31 games due to left knee bursitis but showed little discomfort in belting a solo shot off Yovani Gallardo in the first inning.
Washington knocked Gallardo (6-8) out during the fourth having pelted him for eight runs on nine hits to build a healthy lead it never relinquished.
Jayson Werth went 2-for-5 with five RBI to highlight a 13-hit effort behind Zimmermann (12-3), who remained unbeaten in 10 starts at Nationals Park this season following a so-so outing that saw him surrender four runs on nine hits.
Rickie Weeks and Juan Francisco both homered for Milwaukee, but the club matched a season-high with its sixth straight loss.
Washington went a mediocre 15-16 while Harper was on the disabled list but were coming off consecutive series victories over the Diamondbacks and Mets, including a 13-2 thumping of New York on Sunday.
The reigning NL Rookie of the Year looked to keep the winning ways going when he smacked a fastball just over the wall in left-center in the first inning for his 13th home run of the season.
Harper's teammates got in on the act in the third, including Zimmermann, who led off with the first of four doubles in the five-run frame. After Denard Span walked, Werth hit one deep into the left-field gap to bring in a pair.
Ryan Zimmerman added an run-scoring single, and Adam LaRoche and Ian Desmond hit back-to-back RBI doubles to extend Washington's cushion.
Werth again knocked in Zimmermann and Span in the fourth, this time with a single to chase Gallardo and give the Nationals a comfortable 8-0 lead.
Milwaukee, after failing to score in the last 12 innings of their 14-inning loss to Pittsburgh on Sunday, finally broke its scoring drought in the fifth, as Norichika Aoki singled in Francisco and Sean Halton scored on Jean Segura fielder's choice grounder.
Weeks and Francisco launched back-to-back long home runs in the sixth, and the Brewers kept chipping away an inning later when Aramis Ramirez doubled into the left-field corner to knock in Carlos Gomez.
But that's as close as Milwaukee got.
Drew Storen stranded Ramirez on second, Tyler Clippard tossed a 1-2-3 eighth, and the Nationals tacked on two in the bottom half against Johnny Hellweg. Segura couldn't handle Werth's grounder with runners on the corners, allowing Roger Bernadina to score, and Zimmerman accounted for the final margin with an RBI single.
Zimmermann has already matched his win total from last season and has not lost since May 29. The right-hander has not lost at home since May 17, 2012 against the Pirates, a span of 21 starts ... Burke Badenhop and Tom Gorzelanny each tossed two scoreless innings in relief behind Gallardo ... The teams combined for 24 hits ... Segura committed two errors.