OAKLAND -- Matt Chapman doubled in the go-ahead run in the sixth inning to make a winner of Paul Blackburn in his first start of the season, and the Oakland Athletics beat the Kansas City Royals 4-1 on Thursday night.
Matt Olson hit his 13th home run, Stephen Piscotty singled three times and Marcus Semien added two hits and an RBI to help the A's to their third win in four games against the Royals over the past seven days.
Blackburn (1-0) was reinstated from the disabled list before the game after missing the first two months of the season with a strained right forearm he suffered late in spring training. The right-hander yielded three hits, including Alcides Escobar's home run in the third and induced 11 groundouts over six innings.
Kansas City's Jason Hammel (2-6) matched Blackburn until Oakland broke through for three runs in the sixth.
After Hammel retired Jed Lowrie on a fly ball, Khris Davis singled and moved to second when Olson walked. Chapman then hit a towering fly ball that hit near the top of the wall. Royals center fielder Paulo Orlando appeared to have a good jump on it but got twisted around near the wall before the ball ricocheted off the fence, allowing Davis to score.
Semien and Piscotty followed with back-to-back RBI singles.
Oakland finished with nine hits. In doing so, the A's avoided becoming the first team since the 1910 Chicago White Sox to go 14 consecutive games at home with seven or fewer.
Hammel allowed four runs on eight hits in six innings against his former club. He struck out six and walked one.
The Royals have lost five straight.
Olson's home run off Hammel in the fourth extended his hitting streak to a career-high seven games.
Royals: Orlando was recalled from Triple-A Omaha before the game and took the roster spot left vacant when Jon Jay was traded to Arizona in exchange for a pair of minor leaguers Wednesday.
Athletics: Catcher Bruce Maxwell was optioned to Triple-A Nashville. ... OF Boog Powell (sprained right knee) was transferred to 60-day disabled list. ... RHP Santiago Casilla (shoulder strain) is expected to come off the DL soon.
RHP Frankie Montas (2-0, 0.64 ERA) pitches for Oakland on Friday night. Montas has allowed one run over 14 innings since being called up from the minors May 27. The Royals counter with RHP Jakob Junis (5-5, 3.62).