SEATTLE — Khris Davis hit a three-run homer, Paul Blackburn pitched one-run ball into the eighth inning for his first major league victory and the Oakland Athletics beat the slumping Seattle Mariners 7-4 on Thursday night.
Davis' 24th homer propelled a four-run fifth inning that put the Athletics in front 7-0. Marcus Semien, activated off the disabled list Thursday, singled to open the inning, and Yonder Alonso walked. Davis, who struck out in his first two at-bats, then sent a 1-1 pitch over the wall in center to make it 6-0. Bruce Maxwell added a two-out solo homer, his first, to chase starter former Ashland star Sam Gaviglio (3-4).
The only run off Blackburn (1-0) was Mitch Haniger's seventh home run, a solo shot in the fifth. Blackburn allowed eight hits, did not strike out a batter and walked one over 7 2/3 innings in his second consecutive strong start. He gave up one unearned run in six innings without a decision in his debut on Saturday.
Seattle has lost four straight and nine of 11 since reaching a season-best two games above .500 on June 23.
The Mariners pulled within 7-4 in the ninth on a three-run homer by Danny Valencia, his ninth, off Daniel Coulombe. Santiago Casilla got the final two outs.
Gaviglio was tagged for seven runs and nine hits in 4 2/3 innings in losing his third consecutive start. He walked three and struck out six.
The Athletics jumped on Gaviglio for three runs in the first. Matt Joyce singled, Semien walked and Alonso doubled to make it 1-0. After Davis struck out, Jed Lowrie one-hopped a two-run double off the wall in right-center.
Blackburn was aided by double plays in each of the first two innings, followed by a pair of baserunning blunders by the Mariners. Haniger doubled to open the third, but then was thrown out at third base trying to advance on a fly out to center. In the fourth, Jean Segura singled to lead off, but he was picked off first and caught in a rundown.
Semien was activated off the 60-day DL (fractured bone in right wrist) and RHP Jharel Cotton was placed on the 10-day DL (right thumb blister). Semien missed 74 games. "You look at our lineup and all of a sudden it looks like it's got a little more length and some more oomph in it," manager Bob Melvin said. "So, it's good to get him back. Obviously, we've missed him." Cotton is 5-8 with a 5.17 ERA in 14 starts. RHP Andrew Triggs was transferred from the 10-day DL to the 60-day DL (strained left hip).
Athletics: RHP Ryan Dull (strained right knee) is scheduled to throw live batting practice in Arizona on Saturday, Melvin said. ... RHP Kendall Graveman (strained right shoulder) was scheduled to throw two 20-pitch bullpen sessions in Arizona on Thursday. ... INF Chad Pinder (strained left hamstring) "is hitting in the cage and running much better now, so that's a step forward," Melvin said.
Mariners: DH Nelson Cruz has been hampered by a sore right knee. Cruz was thrown out at second trying for a double on a drive off the wall in left-center in Wednesday's 9-6 loss to Kansas City. "He's managing it best he can," manager Scott Servais said. "I appreciate him doing everything he can to get on the field. We know that's it a deficiency when he's on the bases, but we're taking the good over the bad right now and the good is him in the batters' box."
Athletics: Left-hander Sean Manaea (7-4, 3.75 ERA) is 6-1 with a 2.84 ERA over his last nine starts. He is 1-1 in two starts this season against Seattle.
Mariners: Left-hander James Paxton (6-3, 3.27) still is looking for the early season form displayed before spending most of May on the disabled list. He was 3-0 with a 1.43 ERA in six starts before going on the DL, 3-3 with a 5.15 ERA in seven starts since returning.