Marlins first baseman Justin Bour also had a big game, belting two homers and driving in four runs. He leads the team with 12 homers.
Baltimore's Mark Trumbo went 3-for-4 with his fourth homer of the season and two RBIs, helping power Baltimore to its first win at Camden Yards since May 13.
Orioles' starter Dylan Bundy (5-7) earned his first win since he beat the New York Mets 1-0 on June 6. The Orioles started their nine-game losing streak the next day.
On Sunday, Bundy allowed five hits, two walks and four runs in six innings. He struck out five but allowed both of Bour's homers.
Marlins rookie right-hander Trevor Richards (1-4) took the loss and lasted just 3 1/3 innings, allowing nine hits, one walk and six runs.
Richards got in trouble in the second when Trumbo hit a leadoff single and Jonathan Schoop doubled down the third-base line. Both runners scored on Peterson's one-out, ground-rule double to right-center.
Baltimore doubled its lead in the third. The rally started with two outs and nobody on as Manny Machado punched an opposite-field single, and Trumbo hit an RBI double that hit the tip of left fielder Derek Dietrich's glove before bouncing off the wall. After Schoop walked, Trey Mancini grounded a single to center to make it 4-0.
Miami cut its deficit to 4-1 in the fourth as Bour pulled a homer to right on a 1-0 fastball.
But Baltimore knocked Richards out of the game in the bottom of the fourth, getting singles by Craig Gentry and Austin Wynns and a two-run double to right-center from Adam Jones.
In the fifth, the Orioles put up a two-spot for the fourth straight inning. Schoop drew a leadoff walk, and Peterson blasted his homer to right.
Miami cut its deficit to 8-4 in the sixth as Bour's second homer followed a leadoff single by Dietrich and a walk to Brian Anderson.
Miami wasted a golden opportunity in the seventh, loading the bases with no outs but failing to score. Reliever Mychal Givens inherited the jam from Miguel Castro and got two quick outs with no advancement. Lefty Tanner Scott then came in to face the left-handed Bour and struck him out looking.
The Orioles put the game away with two runs in the eighth, benefitting from Trumbo's homer and Machado's RBI single.
--Field Level Media
Miami | Baltimore | |
Trevor Richards | Player | Dylan Bundy |
Loss | W/L | Win |
3.1 | IP | 6.0 |
2 | Strikeouts | 5 |
9 | Hits | 5 |
16.20 | ERA | 6.00 |
Miami | Baltimore | |
Derek Dietrich | Player | Mark Trumbo |
2 | Hits | 3 |
0 | RBI | 2 |
0 | HR | 1 |
2 | TB | 7 |
.667 | Avg | .600 |