BALTIMORE — Jackie Bradley Jr. hit a pair of three-run homers, Mookie Betts homered and had three RBI, and the Boston Red Sox used their most prolific offensive performance of the year to blow out the Baltimore Orioles 17-6 Saturday night.

Rafael Devers and Sandy Leon also went deep for the Red Sox, who are 10-5 in July.

Bradley’s second home run of the game highlighted an eight-run fourth inning that turned a tie into a 13-5 runaway. All eight runs were unearned, courtesy of a throwing error by shortstop Richie Martin.

Boston really didn’t need the help. Betts and J.D. Martinez had three hits apiece, every starter scored at least once, and the Red Sox amassed nine extra-base hits.

It was Boston’s highest-scoring outburst since a 19-3 rout of Baltimore last Sept. 26.

Rick Porcello (8-7) was the beneficiary of the robust support. The right-hander won his third straight start despite giving up six runs and 11 hits in five innings.

Anthony Santander had a career-high four hits, including a home run, and Renato Núñez also connected for Orioles. But that wasn’t nearly enough pop to offset a pitching staff that allowed a season high in runs after surrendering 16 three times previously.

Bradley’s first home run, off rookie Tom Eshelman (0-2), capped a four-run second inning. Devers hit his 20th of the season leading off the third, but Baltimore answered with five runs in the bottom half.

Boston hammered Eshelman and Jimmy Yacabonis in the pivotal fourth and continued the onslaught in the fifth. Yacabonis got one out and yielded seven runs and eight hits.

Infielder/outfielder Stevie Wilkerson pitched the final two innings, throwing mostly curveballs in the 55 mph range. He gave up a solo shot to Leon.

HOT STUFF

Because of the oppressive heat, the Red Sox skipped batting practice for a second straight day and will do so again Sunday.

Temperature at game time was 97 degrees, and the players were ready for it.

“Obviously, you have to stay hydrated, and that started a couple of days ago,” Orioles outfielder Trey Mancini said. “You have to be drinking water, even when you’re not thirsty.”

The heat wave is expected to last through Sunday afternoon, when the teams conclude the three-game series.

“Day games, it’s tough to stay cool,” Baltimore left-hander Paul Fry acknowledged.

GOING, GOING, GONE!

Adley Rutschman, the top pick in the June draft, hit his first professional homer for the Gulf Coast Orioles on Saturday.

TRAINER’S ROOM

Red Sox: First baseman Michael Chavis left in the fifth inning because of back spasms. … Right-hander Nathan Eovaldi (elbow) was activated from the 60-day IL. “He’s ready to go,” Manager Alex Cora said. Right-hander Ryan Weber was optioned to Triple-A Pawtucket. … First baseman Mitch Moreland (quadriceps) continued his rehab at Pawtucket, going 0 for 3 over seven innings. … Left-hander Brian Johnson (a non-baseball related medical matter) is making progress but needs more reps. Johnson’s ailment was discovered during routine testing by the team’s medical staff. … Right-hander Steven Wright (foot), struck by a comebacker a week ago, might take a bit longer than originally believed to return.