Suarez's homer, his fourth of the season, was a three-run shot to left that followed a Jose Peraza double and Alex Blandino's walk.
Duvall's homer, his fifth, was a solo shot that came three pitches after Suarez went deep. Duvall, however, sent his homer to the opposite field, just over the glove of right fielder Brian Anderson.
The Reds, who are in last place in the National League Central at 8-24, snapped a three-game losing streak. They entered Friday with a 3-12 home record. They had also allowed 30 homers and a 5.54 ERA in 15 games at the Great American Ball Park.
On Friday, however, the Reds got solid starting pitching from right-hander Sal Romano (2-3), who allowed three hits, two walks and one run in 5 1/3 innings.
Four Reds relievers -- Wandy Peralta, David Hernandez, Jared Hughes and Raisel Iglesias -- shut down the Marlins the rest of the way. Iglesias pitched the ninth, earning his fourth save.
The Marlins, who are in last place in the NL East, lost their second straight game following a four-game win streak. Marlins left-hander Wei-Yin Chen, who came off the disabled list last week to allow just one run in 5 1/3 innings against the Colorado Rockies, was ambushed on Friday by those two first-inning homers.
He allowed five hits, four walks and four runs in four innings, striking out two. His ERA climbed from 1.69 to 4.82.
Trailing 4-0, Miami finally got on the board in the fifth inning on Lewis Brinson's solo home run, which was crushed to straight-away center. He hit a 2-2 fastball for his fourth homer of the season.
The Marlins had a chance to do damage in the sixth, loading the bases with one out. But Hernandez came on and retired Anderson on a line drive to shallow left. Martin Prado then flew out to end Miami's last major threat.
--Field Level Media
Miami | Cincinnati | |
Wei-Yin Chen | Player | Sal Romano |
Loss | W/L | Win |
4.0 | IP | 5.1 |
2 | Strikeouts | 2 |
5 | Hits | 3 |
9.00 | ERA | 1.69 |
Miami | Cincinnati | |
Brian Anderson | Player | Jose Peraza |
2 | Hits | 2 |
0 | RBI | 0 |
0 | HR | 0 |
2 | TB | 3 |
.500 | Avg | .400 |
Team | Hits | HR | TB | Avg | LOB | K | RBI | BB | SB | Errors |
Miami | 5 | 1 | 8 | .172 | 14 | 4 | 1 | 3 | 0 | 0 |
Cincinnati | 7 | 2 | 15 | .233 | 18 | 6 | 4 | 7 | 0 | 0 |