OAKLAND, Calif. — It looked like a harmless pop fly to shallow right. But after the ball fell between two fielders, it triggered an avalanche of pain for the Oakland Athletics.

Willi Castro’s gifted double was the beginning of a seven-run second inning for the Twins as they pulled away from the Athletics in a 10-2 win Saturday afternoon at the Oakland Coliseum.

The offensive outburst came in support of starter Bailey Ober, who helped preserve a tired bullpen by tossing the first complete game of his career. Ober appeared to get stronger as the day went on, and he struck out all three batters he faced in the eighth inning. He finished with 10 strikeouts, tying a career high. He needed just 89 pitches to accomplish the feat.

Ober gave up a solo home run in the first inning to JJ Bleday, tying the game at the time, and a leadoff home run to Tyler Soderstrom an inning later. But for the most part, the starter was dominant, stifling the Athletics — he retired the last 17 batters he faced in order — while pitching with a healthy lead.

Castro’s double in the second set off a streak of six batters in a row to reach base. During that stretch, Manuel Margot hit a three-run home run and Jose Miranda sent a double to the gap, bringing home another pair of runs.

Later in the inning, Byron Buxton drove in a run with a double and Kyle Farmer had a run-scoring single, helping put the game firmly out of reach with the way Ober was throwing the ball.

Margot and Miranda each finished with three hits and three RBIs while Carlos Correa added three hits of his own and Royce Lewis went 2 for 5.