BOSTON (Interstat) — Kyle Bradish pitched seven strong innings and the Baltimore Orioles erupted for four runs in the first inning to defeat the Boston Red Sox 5-1 on Wednesday in the first game of a day-night doubleheader at Fenway Park.

Bradish scattered five hits, walked one and struck out six to improve to 7-9. He allowed only one run, a fourth-inning RBI single by Masataka Yoshida. Yennier Cano worked two scoreless innings to close out the victory.

Eduardo Rivera took the loss in his major league debut, retiring just two batters. The right-hander faced eight Orioles in the first inning, allowing three hits and four earned runs with one strikeout. Rivera fell to 0-1.

Baltimore jumped on Rivera immediately. After Taylor Ward flied out to lead off the game, Pete Alonso doubled to right field. Gunnar Henderson walked and Tyler O’Neill reached on a fielder’s choice as third baseman Caleb Durbin could not turn the double play, loading the bases. Christian Encarnacion-Strand struck out for the second out, but Dylan Beavers lined a two-run single to center field, scoring Henderson and O’Neill. Johnathan Rodríguez followed with an RBI double to left, scoring Beavers to make it 4-0.

The Orioles tacked on an insurance run in the seventh. Henderson led off with a triple to center field, his third of the season. Colton Cowser walked, and after a sacrifice bunt and a groundout, Henderson scored on a fielder’s choice groundout by Dylan Beavers. That run gave Baltimore a 5-1 lead.

Boston’s only run came in the fourth. Willson Contreras led off with a ground-rule double down the right-center field gap. Yoshida singled to left, plating Contreras to cut the deficit to 4-1. But Bradish retired Durbin on a groundout to shortstop to end the inning.

The Red Sox managed little else off Bradish. Andruw Monasterio had two hits for Boston, including a single in the third that was erased on a strong throw from left fielder Taylor Ward to second base. Anthony Seigler singled in the eighth but was stranded. Boston went 1 for 3 with runners in scoring position and left five men on base.

Baltimore’s offense collected nine hits. Beavers had two hits and two RBIs. Rodríguez doubled and drove in a run. Alonso doubled and scored once. Henderson reached base three times on a triple, a walk and a hit by pitch, scoring two runs. The Orioles also drew four walks and stole a base.

For Boston, Brayan Bello provided length in relief, working 5 1/3 scoreless innings with four hits allowed and five strikeouts. Alec Gamboa tossed a perfect inning with one strikeout. Jovani Morán allowed one earned run on one hit in the seventh.

The victory snapped a modest two-game losing streak for Baltimore, which improved to 50-53. The Orioles had lost 6-5 to the Red Sox on Monday in the series opener. Boston fell to 52-49.

The Orioles took an early lead through a combination of disciplined at-bats and timely hitting. After Rivera struggled to find the strike zone, the Orioles capitalized on the mistakes. The four-run first inning tied Baltimore’s highest single-inning output in its last 10 games.

Bradish, a right-hander, worked efficiently after the rocky first inning from his offense. He retired nine of the first 10 batters he faced, allowing only a walk to Durbin in the second. Through the first three innings, Bradish faced the minimum, thanks to Ward’s assist to erase Monasterio on the basepaths in the third.

Boston threatened again in the sixth when Contreras was hit by a pitch with two outs, but Yoshida grounded out to second to end the inning. Bradish completed seven innings for the fourth time this season.

The Orioles managed only one hit after the third inning but broke through again in the seventh. After Henderson’s triple, Cowser drew a four-pitch walk from Morán. Encarnacion-Strand sacrificed, moving Cowser to second. Beavers then grounded to first baseman Contreras, who threw to Morán covering first for the out, but Henderson scored easily on the play.

Baltimore’s bullpen remained solid. Cano worked around a hit-by-pitch in the ninth, retiring the next three batters to seal the win.

In the head-to-head series, the win evened the season record at 3-3. Baltimore had lost three of the previous four meetings before Wednesday.

The Orioles will look to take the second game of the doubleheader later Wednesday. Boston will turn to its bullpen for the nightcap while searching for a split.

Interstat’s game simulator had projected a final score of Boston 7, Baltimore 6, and Interstat’s ELO system gave Boston a 59.00 percent probability to win. The Red Sox were installed as pregame favorites with a spread of minus-1.5. The total score of 6 went over the over-under line of 8.5.