OAKLAND - Yonder Alonso found his power-hitting comfort zone at the Coliseum earlier this season, and it resulted in his first All-Star Game selection.
Now he does his damage in a Mariners uniform, and the A's could do without the power he's shown the past two nights.
Alonso, traded from Oakland to Seattle in August, went deep for the second night in a row Tuesday, and another former Athletic, Danny Valencia, added the knockout blow with a three-run shot to lift the Mariners to a 6-3 victory.
It was a trip down memory lane that A's manager Bob Melvin could have done without. This was a game his team was in position to win, thanks to solid starting pitching from Daniel Mengden, some pretty defensive work behind the pitcher and Khris Davis' 42nd home run, which gave the A's a short-lived 3-2 lead.
"It's a frustrating loss for us," Melvin said. "(Seattle starter James) Paxton is doing his thing, and we finally get him out of the game and take the lead with a two-run homer and we can't hold it. That's the frustrating part."
While the A's recently have dominated at home this season against Texas, which just left the Coliseum on Sunday, the Mariners are one division opponent they simply can't solve. They've dropped an Oakland-record eight in a row to Seattle.
They can thank Alonso and Valencia for Tuesday's heartache. Alonso hardly has torn the cover off the ball with the Mariners - he has just five homers in 39 games since the A's traded him for outfielder Boog Powell. But he's made a good enough impression that there's thought that the Mariners might try to re-sign the free agent-to-be.
His trade to the Mariners reunited him with his longtime friend Valencia, who the A's shipped to Seattle last offseason for right-hander Paul Blackburn. Both took joy in homering in the same game at the Coliseum, though neither was looking to rub it in against their former club.
"I have a lot of love playing here. It's a good place to play," said Valencia, who made headlines last year when he punched then-A's teammate Billy Butler in a clubhouse altercation.
The A's and Mariners have combined for nine homers in the first two games of this three-game set that ends Wednesday afternoon. Marcus Semien hit his first career leadoff homer in the first to accompany Davis' blast, helping the A's establish a new Oakland single-season record for homers at the Coliseum (128).
But, as has been their M.O. all season, if the A's aren't clearing the fences, they aren't doing enough offensively. They had nine hits total but couldn't push any more runs across.
"Our team's success this year has revolved around the home run," Melvin said. "We need to find other ways to do it."
The A's began this series hoping to catch fourth-place Seattle and escape the AL West cellar. But in taking the first two, the Mariners have leapfrogged Texas into third place for the time being, and the A's trail Texas by four games for fourth place with five left to play, including four against the Rangers in Arlington beginning Thursday.