Nelson admitted, "I didn't have anything," and characterized both of the home run pitches as mistakes.
That was enough offense for Reds starter Michael Lorenzen, who held the Brewers to two runs over 5 1/3 innings and picked up his first win since June 21.
"Nice for him to go out there and give us a really good effort," Reds manager Bryan Price said. "I just thought he did a wonderful job. He mixed all four pitches. He utilized them all."
The loss snapped Milwaukee's six-game winning streak and mathematically eliminated the fourth-place Brewers from the National League Central division race. Nelson allowed five runs on nine hits and two walks over five innings, evening his record at 11-11.
MOMENTS THAT MATTERED Collision course: The Reds' first run came on an unusual infield single. With two on and two outs in the first inning, Bruce hit a hard ground ball past Adam Lind and into shallow right field. But second baseman Scooter Gennett got to the ball, spun and threw toward first. Lind caught the ball in position to get the force out, but Nelson also sprinted over to cover the bag. Bruce bowled over Nelson and was ruled safe, allowing Joey Votto to score from third, a call that stood after a 3-minute, 1-second review initiated by Brewers manager Craig Counsell.
"I couldn't see anything because I was rolling. But while they were challenging it, Adam told me, 'I was on the bag,'" Nelson said. "I was pretty confident, because he will tell you if he was or wasn't on the bag. He doesn't sugarcoat it. When he told me he was on the bag, I thought we were going to get that one. I guess -- I don't know. Were they looking at my feet not being on the bag or something?"
Bruce and the Brewers: Bruce launched his 20th home run to right field off Nelson in the fifth inning. The two-run, 389-foot shot -- the 999th hit of his career -- gave Cincinnati a 5-0 lead and continued Bruce's career-long power surge at Milwaukee's expense. Bruce has slugged 30 homers in 114 career games against the Brewers, 10 more than he's hit off any other team.
"I think that game was all about the middle of their lineup, really," Counsell said. "It's a formidable middle of the lineup. We kept them in check all right [for most] of the season, but I had them on base 13 times -- [Todd] Frazier, Phillips, [Joey] Votto and Bruce. They caused us trouble every time around today."
Making it interesting: Two innings after the Brewers began chipping away with a pair of runs against Lorenzen, Ryan Braun made it a 5-3 game in the eighth by hitting a solo home run off Reds reliever J.J. Hoover, who has been taken deep in three straight appearances. The shot gave Braun 25 home runs and 80 RBIs, and he tops on the team in both categories. He would lead the Reds in RBIs, too.
Chapman slams the door:Aroldis Chapman's appearances have been infrequent lately, but characteristically dominant -- especially against the Brewers. Chapman picked up his 28th save with a perfect ninth inning that included two strikeouts. Chapman has held Milwaukee's current crop of hitters to four hits in 45 at-bats while striking out 30.
QUOTABLE "Our job is still to win games, no matter how good or bad it's going. It's good to come out and take care of business today." --Bruce
WHAT'S NEXT Brewers: Counsell will manage his first games in Miami, where he became a World Champion, when the Brewers visit the Marlins for a three-game set beginning Monday at 12:10 p.m. CT. A Marlins fan-favorite, Counsell tied Game 7 of the 1997 World Series with a ninth-inning sacrifice fly, then scored the winning run in the 11th. Now he's a manager, who will send 22-year-old Zach Davies to the mound in the series opener for Davies' second big league start.
Reds: The Reds will remain at Great American Ball Park for their fourth of five straight National League Central matchups, welcoming the Pirates for a three-game series beginning with Monday's Labor Day matinee at 1:10 p.m. ET. Right-hander Anthony DeSclafani, who has recorded a 3.18 ERA without a win in three outings against the Bucs this season, is slated to start.