BOSTON (AP) — Colton Cowser hit the first two homers of his career, including a three-run shot in the 10th inning, and the Baltimore Orioles rallied past the Boston Red Sox 9-4 on Thursday night to complete a three-game sweep of their AL East rivals.

Gunnar Henderson opened the Orioles’ six-run 10th with a two-run homer against Isaiah Campbell (0-1), scoring automatic runner Jackson Holliday.

The 20-year-old Holliday, baseball’s top-rated prospect who made his big league debut a night earlier, scored two runs but went 0-for-4 for the second straight game.

Cowser, another Orioles prospect who struggled during a brief stint in the majors last season, drove in 10 runs in the series.

A night after the Orioles rallied from a 5-0 deficit to win 7-5, they fell behind 2-0 before coming back, thanks in part to some shaky defense by the Red Sox.

Boston led 2-1 when Holliday reached on an error by third baseman Pablo Reyes leading off the eighth. With one out, Adley Rutschman hit what appeared to be an inning-ending double-play grounder, but the Orioles challenged the call, and after a review, Holliday was ruled safe at second because shortstop David Hamilton missed the bag while making the turn.

Reliever Greg Weissert came in, and Anthony Santander hooked his first pitch around the foul pole in right for a two-run homer that made it 3-2.

Pinch-hitter Connor Wong tied it with two outs in the eighth with a homer over the Green Monster off Danny Coulombe. It was Wong’s first homer of the season and first career pinch homer.

Craig Kimbrel (2-0) worked a scoreless ninth.

Orioles starter Grayson Rodriguez worked 5 2/3 innings, allowing both of his runs in the first.

Garrett Whitlock lasted five innings for Boston and gave up Cowser’s first homer, a solo shot.


Orioles: LHP John Means (left forearm strain) made his third rehab start on Thursday, going three innings for Triple-A Norfolk. He gave up two runs on two hits.

Red Sox: 3B Rafael Devers sat out with left shoulder soreness, and manager Alex Cora said a stint on the injured list was possible. … INF/OF Romy Gonzalez will get X-rays on his left wrist, which he tweaked on Wednesday.


Orioles: Holliday will make his home debut when Baltimore hosts Milwaukee on Friday. RHP Tyler Wells (0-1, 4.76 ERA) is scheduled to start against Brewers RHP Freddy Peralta (1-0, 3.09).

Red Sox: Host the Los Angeles Angels in the opener of a three-game series. Boston RHP Tanner Houck (2-0, 0.00) is scheduled to face LHP Reid Detmers (2-0, 1.64).