Dunn, hitless in his first two at-bats to extend his slump to 0-for-23, led off the seventh with a drive into the right-field stands off Zach Day (3-6).
Asked if he thought he’d get another hit this season, Dunn wasn’t as confident as Griffey was.
“No I didn’t, but Junior told me I was going to get one today, I think he told me (Friday) night,” Dunn said.
It was Dunn’s 12th homer of the season and first hit since May 22, when he went 2-for-2 in an 8-7 win over Houston.
“I told him after the game, ‘You get to play tomorrow,”’ Reds manager Dave Miley said. “That was a big, big home run.”
Cincinnati, the surprise NL Central leaders, have won nine of 11 and are tied with Florida for the league’s best record at 29-20.
Acevedo (3-3) scattered five hits—including Endy Chavez’s solo homer in the sixth—in seven innings for his first win in seven starts since April 20.
“All my pitches were right there,” Acevedo said. “I threw some changeups, some curves and some sliders, and everything worked.”
Danny Graves pitched the ninth for his second straight save and major league-leading 23rd in 27 opportunities.
Montreal has lost three in a row, and eight of nine. The Expos fell to a NL-worst 15-33.
“I don’t see any fire, no intensity,” manager Frank Robinson said. “Nobody’s getting (upset). I’m not saying they’re giving up but when they start to accept losing, it’s not very good. You don’t see light at the end of the tunnel.”
Reds right fielder Austin Kearns missed the game because of an open sore on his right thumb.
Day, who walked six in seven innings, held Cincinnati to one hit—Ryan Freel’s leadoff single in the first—through the first six innings.
The Expos walked a season-high eight batters. Sun-woo Kim walked two while getting just one out in relief of Day.
Freel opened the scoring in the sixth as the Reds manufactured a run without a hit. Freel walked to lead off the inning and stole second, his eighth steal of the season. He advanced to third on Barry Larkin’s grounder to second and scored on Sean Casey’s RBI grounder.
“They did the right thing,” Day said. “I walked somebody, they got him over and on two groundballs, they’re scoring. The home run, I’ll take a solo home run, I’m going to give up those, I’m not going to be perfect every time but they did the little things to pull it off.”
Chavez hit his third homer of the season with one out in the bottom half to tie it at 1.
Dunn’s homer restored Cincinnati’s one-run lead and the Reds made it 3-1 later in the inning when Jacob Cruz scored on Day’s wild pitch past catcher Brian Schneider on an 0-2 pitch to Freel with two outs and runners on second and third.
Day, 1-5 in his last six starts, allowed three runs and three hits. He struck out five.
D’Angelo Jimenez hit an RBI double off Kim in the eighth to drive in the Reds’ fourth run.
Montreal’s Nick Johnson singled in the fifth for his first NL hit. Johnson, who popped out in the second after going 0-for-3 in his Expos debut Friday,doubled in the seventh.
Kearns will be rested Sunday and reevaluated Monday in Florida. … Reds center fielder Griffey made an over-the-shoulder catch just short of the warning track on Brad Wilkerson’s fly an at-bat before Chavez’s homer. … The Expos did not make an error for the 32nd time in 48 games. Montreal hascommitted a major league-low 18 errors.