Rooker’s two-run drive off Griffin Canning in the fourth inning, was his eighth in 56 games at home and put the A’s ahead for good.

Blackburn (4-4) allowed four hits and one run with four strikeouts, raising his season total to a career-high 90.

One day after matching an Oakland-era record with eight doubles in the series opener, the A’s were limited to five total hits but made them pay off.

Pitching made the biggest difference for manager Mark Kotsay’s team as five relievers followed Blackburn and combined for four innings of two-hit ball. Trevor May recorded the final three outs for his 16th save.

Mike Moustakas had two hits for the Angels while Luis Rengifo extended his hitting streak to 10 games, matching his career high.

Northern California native Kyren Paris got his first major league hit, a day after making his debut with Los Angeles.

Ohtani, the two-way Japanese star whose is facing a possible second Tommy John surgery after suffering a torn UCL earlier this month, leads the majors with 44 home runs but went 0 for 2 with three walks — two intentional.

Canning (7-5) struck out seven but allowed four hits and two runs in six innings. The right-hander, who beat the A’s earlier this season, remains winless in five career starts at Oakland.

The Angels got the tying run on in the ninth when pinch-hitter Michael Stefaic walked and advanced to second on a sacrifice bunt. After Nolan Shanuel grounded out, Ohtani was intentionally walked by May, drawing boos from the crowd of 13,709. Brandon Drury then flew out to end it.

The Angels began the game with back-to-back walks off Blackburn followed by a one-out broken-bat single from Moustakas. A’s shortstop Nick Allen then made backhanded grab of Rengifo’s short pop-up into the outfield grass but slipped and fell as Schanuel scored.