Corey Kluber, meet Matt Chapman.
The A's rookie third baseman made an indelible impression on the 2014 Cy Young Award winner Saturday night, hitting his first two big-league homers against Kluber and adding a double that led to third run.
Chapman's second homer, on the first pitch of the eighth inning, tied a game that A's won 5-3 in the ninth on Khris Davis' two-run, opposite-field homer against Bryan Shaw.
After Ryan Madson's perfect ninth for the A's, whose bullpen did not allow a baserunner in three innings, Andrew Miller started the bottom half by walking Yonder Alonso,
Davis then sent his 25th homer over the wall in right-center to start a celebration at the Coliseum in front of 33,021 fans and secure a series victory against the defending American League champs to start the second half.