BOSTON — Rafael Devers had a career-high eight RBIs, hitting a three-run homer in the sixth inning and a grand slam in a 13-run eighth, to lead the Boston Red Sox over the Baltimore Orioles 19-5 on Friday in the opener of what was supposed to be a day-night doubleheader.

Boston trailed 2-1 entering the sixth, when Ceddanne Rafaela hit an RBI single off Seranthony Dominguez (2-1), Jarren Duran had an RBI single against Gregory Soto and Devers followed with his fifth homer in 10 career at-bats against Soto.

Devers had four hits and leads the major leagues with 47 RBIs. He hit his seventh career slam and his second in a six-day span, his 12th homer this season. The drive came off rookie infielder Emmanuel Rivera, who gave up eight runs and got three outs, leaving him with a 72.00 ERA. Devers hit an RBI single earlier in the inning against Cionel Pérez.

“Everybody is surprised about what he’s doing, but that’s who he is,” said Red Sox starter Brayan Bello, according to MLB.com. “Everybody was also surprised he got off to a slow start in the first five or six games, but we know the type of hitter that he is, the type of player that he is and the numbers he can put up.”

Boston scored its most runs since a 20-8 win over the Toronto Blue Jays on Aug. 11, 2021, and finished with 20 hits.

Its 13 runs in the eighth inning are the franchise’s second most in an inning over the past 50 seasons (14 on June 27, 2003, against the Marlins). They were also the most runs by any team in the eighth inning or later since the New York Yankees on June 21, 2005, against the Tampa Bay Rays (also 13).

Baltimore has lost nine of 10 and and 15 of 18, dropping to 16-33. The Orioles are 1-5 since manager Brandon Hyde was fired and replaced on an interim basis by third-base coach Tony Mansolino.

Red Sox third baseman Alex Bregman left because of right quadriceps tightness after singling in the fifth inning.

Rob Refsnyder had four RBIs, including a three-run homer in the eighth off Pérez. Duran had three RBIs.

The Red Sox had eight players score multiple runs, one shy of tying the franchise record.

Garrett Whitlock (3-0) allowed one hit in two scoreless innings.

Game 2 of the scheduled doubleheader was postponed later Friday because of rain. The teams will play a split doubleheader Saturday (1:05 p.m., 6:35 p.m.).

Information from ESPN Research and The Associated Press was used in this report.

Mired in a nine-game losing streak, the Athletics shook up their roster Friday and called up five players, including highly touted prospect Denzel Clarke.

Veteran Seth Brown was designated for assignment amid moves that general manager David Forst hopes will give the club more flexibility.

“Ultimately, obviously we’re in a stretch right now we’re not finding ways to win,” Forst said in a video news conference. “I think we’re better than we’ve shown the last 10 days.”

Clarke, a 25-year-old center fielder known for his standout defense, speed and power, was the team’s fourth-round selection in the 2021 amateur draft. He was set to start and make his major league debut Friday night for the A’s (22-29) in the opener of a three-game home series against the Philadelphia Phillies at home in West Sacramento.

Clarke was batting .286 with no home runs, 21 RBIs and seven stolen bases in 31 games with Las Vegas. His .436 on-base percentage ranked fourth in the Pacific Coast League.

Also recalled from Triple-A Las Vegas were left-hander Jacob Lopez and infielder CJ Alexander, while catcher Willie MacIver and infielder Logan Davidson were selected from Las Vegas.

During the skid, the club has been outscored 72-26, is batting .209 and has a team ERA of 8.23 while allowing 23 home runs.

Outfielder JJ Bleday was optioned to Triple-A along with right-hander Carlos Duran and catcher Jhonny Pereda. The A’s also transferred second baseman Zack Gelof to the 60-day injured list.

Forst said Bleday needed a “reset” to find a rhythm at the plate and on defense — something he couldn’t find playing every day at the big league level right now. Manager Mark Kotsay spoke to Bleday on Friday about the move.

“Hopefully he’ll be back here very soon,” Forst said.

Third baseman Gio Urshela was placed on the 10-day injured list after straining his left hamstring in a loss to the Los Angeles Angels on Thursday. He underwent an MRI on Friday.

Urshela left the game in the sixth inning with the injury of the 10-5 defeat.

Urshela went 1 for 2 with a bases-loaded walk in the game. He is batting .224 with no homers and 13 RBIs in 32 games this season.

The 32-year-old Brown had been the longest-tenured player on the team but struggled to get regular opportunities. He spent time in the minor leagues last year for a stretch, and Forst remained hopeful he would clear waivers and play for Las Vegas before returning at some point to the A’s.

He was hitting .192 with a home run and three RBIs in 33 games.

NEW YORK — Shohei Ohtani is scheduled to face hitters Saturday for the first time in his recovery from right elbow surgery.

The two-way superstar will throw live batting practice at Citi Field before the Los Angeles Dodgers play the New York Mets, manager Dave Roberts announced Friday.

It’s the next step for Ohtani as he works toward returning to the mound. He had right elbow surgery Sept. 19, 2023, and hasn’t pitched in a major league game since Aug. 23 that year for the Los Angeles Angels.

There is no target date for his pitching debut with the Dodgers, though expectations are that it could come in July.

Roberts said he wasn’t sure how many pitches Ohtani will throw Saturday or which Dodger teammates he will face.

The right-hander mixed in breaking pitches during a throwing session Tuesday for the first time in his rehabilitation program. Before that, he had been limited to fastballs and splitters.

Ohtani threw a 50-pitch bullpen last Saturday, increasing from 35 pitches in his previous session.