BALTIMORE (AP) — Mitch Keller struck out a career-high 13 in his second straight outstanding start, and the slumping Pittsburgh Pirates won for only the second time in 13 games, 4-0 over the Baltimore Orioles on Sunday.

The Pirates avoided a sweep after dropping the first two games of the series. Pittsburgh was 20-8 after a 16-1 win at Washington on April 29. Then the Pirates scored just 18 runs in their next 12 games.

They managed four Sunday without a single extra-base hit, and that was plenty the way Keller (5-1) was pitching. The right-hander allowed four hits in seven innings and did not walk a batter.

Keller was also responsible for Pittsburgh’s only other win so far in May. In his previous start Monday, he shut out Colorado 4-0 for his first career complete game.

On Sunday, Keller pitched more than six innings for only the fifth time in his career, but the third time this season. He struck out Gunnar Henderson, Ryan Mountcastle and Kyle Stowers three times each. Mountcastle also whiffed against reliever Colin Holderman, and Stowers fanned in the ninth against closer David Bednar with two on and nobody out as Baltimore attempted a last-ditch rally.

Kyle Gibson (4-3) allowed four runs, seven hits and three walks in five innings for the Orioles.

Carlos Santana opened the scoring in the first with an RBI grounder, then the Pirates added three runs in the third. Bryan Reynolds, who reached when he struck out on a wild pitch, scored on a single by Ke’Bryan Hayes. Ji Hwan Bae added a two-run single with two outs.

Orioles catcher Adley Rutschman, who has played in every game this season, pinch-hit in the ninth and popped out to end the game.

TRANSACTIONS

The Orioles recalled infielder Joey Ortiz from Triple-A Norfolk and optioned left-hander Nick Vespi to Norfolk. Catcher Luis Torrens cleared outright waivers and elected free agency instead of accepting an assignment to Norfolk.

TRAINER’S ROOM

Orioles: RHPs Mychal Givens (left knee inflammation) and Dillon Tate (right elbow flexor strain) are expected to pitch Tuesday for Norfolk.

UP NEXT

The Orioles host a four-game series with the Angels that begins Monday night with a marquee pitching matchup. Shohei Ohtani (4-1) starts for Los Angeles against Baltimore rookie Grayson Rodriguez (2-0).

Pittsburgh is off Monday. The Pirates play at Detroit on Tuesday night, with Luis Ortiz (0-1) taking the mound for Pittsburgh against Michael Lorenzen (1-2).