He hit .444 (12 for 27) with four homers and 14 RBI during the Brewers' 4-2 road trip to Cincinnati and Washington. Milwaukee is in second place in the NL Central, five games behind Chicago, but it moved a half-game ahead of St. Louis for the first wild card spot.
"We had every kind of game you can have here," Yelich said. "Some rain, we had some extra-inning ones with Cincinnati. Overall, it was a good trip."
Things haven't gone so well for Washington, which dipped back below .500 and has dropped three of its last four. The Nationals walked 11 batters Sunday, matching the team record since the club moved to Washington in 2005.
Starter Jefry Rodriguez (2-2) issued seven walks while allowing seven runs in 4 2/3 innings.
"All I was really trying to do was get ahead on the hitters and throw the ball pretty much own the middle," he said.
It didn't work out that way, but he wasn't hit hard until the fifth. Working with a 4-2 lead, Rodriguez retired two of the first three batters that inning, but yielded a Manny Pina single and then Broxton's blast to center.
Manager Dave Martinez pulled Rodriguez after another single and a walk, but reliever Tim Collins fared no better. His first six pitches were balls. Yelich hammered the seventh to left center for his 27th homer. The seven-run outburst matched Milwaukee's highest-scoring inning of the season.
Yelich has reached base safely in 19 consecutive games and has homered nine times in that span.
"He's clearly taken a jump in his offensive play," Milwaukee manager Craig Counsell said. "The second half has been something to behold. The home runs are coming at a pretty good pace and he's having moments, especially on this road trip, where he's doing kind of superhuman things, really cool things, `He didn't just do that' kind of things."
Reliever Brandon Woodruff (3-0) pitched four scoreless innings to earn the victory.
"This is Brandon Woodruff's game," Counsell said. "I know Yeli hits a home run and Brox hits a three-run homer, but to deliver four innings of scoreless relief in that situation is absolutely huge."
Milwaukee starter Junior Guerra allowed four runs in three innings.
Brewers: Milwaukee's active roster is at 34 after recalling RHP Corey Knebel from Triple-A Colorado Springs and RHP Zach Davies from Class A Wisconsin. INF/OF Nick Franklin was activated from the 60-day disabled list and outrighted to Colorado Springs.
Nationals: LHP Sean Doolittle (left toe inflammation) threw a simulated game Sunday. Martinez said he hopes Doolittle will be activated later this week. . RHP Erick Fedde (shoulder), on the disabled list since July 5, will be activated and start Tuesday against St. Louis.
Broxton was 1 for 11 this season with runners in scoring position, including grounders to end the first and third innings, before his homer in the fifth.
"I had men on base all day today," Broxton said. "Those are the times I'm talking about, when we need those runs. I'm glad I was able to come up the third time around and get those guys in."
RHP Austen Williams pitched two innings in his major league debut, the beginning of what figures to be a month-long audition for a spot in the Nationals' bullpen next season. He struck out Mike Moustakas to open his appearance and finished with two strikeouts and two walks.
"It's awesome," Williams said. "It's hard to describe it other than that. It's a special moment in my life and something I've worked really hard to achieve."
Brewers: Davies (2-5, 5.23 ERA) hasn't started a major league game since May 29 because of a shoulder injury and will get the ball Monday as Milwaukee begins a three-game series at home against the Chicago Cubs.
Nationals: RHP Max Scherzer (16-6, 2.22), who is one strikeout away from his fifth 250-strikeout season in a row, starts Monday against St. Louis as Washington's 10-game homestand continues.
The Texas Rangers have fired manager Jeff Banister after four seasons, the team announced Friday.
If not for the pesky Pittsburgh Pirates, the Milwaukee Brewers might be leading the National League Central, or at least running neck-and-neck with the first-place Chicago Cubs.
For the first time in a month, the Chicago Cubs will play after an off-day as they head into the stretch run of what they hope leads to their third straight National League Central Division title.
The New York Mets dinged Max Scherzer's Cy Young chances Thursday night.
Trevor Bauer will take the mound Friday night for the first time in more than a month as the Cleveland Indians host the Boston Red Sox in the first contest of a three-game series at Progressive Field.
Melisa Reidy-Russell detailed allegations of abuse during her marriage to Addison Russell, which led to the Cubs shortstop being put on leave by MLB.