SEATTLE -- Catcher Omar Narváez closed out his first half with another strong showing at the plate, but the Mariners couldn’t overcome a rough start by opener Matt Carasiti in a 7-4 loss to the A’s on Sunday at T-Mobile Park.

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The Mariners head to the All-Star break with a 39-55 record after losing eight of their last 10 games.

Narvaez, one of Seattle's key additions this season, went 4-for-4 with two home runs and all four RBIs, while hiking his average to a team-leading .294. His 14 homers on the season breaks Mike Zunino’s club record of 13 home runs by the All-Star break for a catcher. The 14 homers in 76 games are two more than he totaled in 221 games over his previous three seasons in the Majors with the White Sox.

“Omar had a great game. He did it all,” manager Scott Servais said. “He can really hit. He’s certainly earned everybody’s respect in the batter’s box. Really good first half by him. We’ve seen more power than we were expecting, so a lot of positives offensively for Omar.”

Narvaez is just the second catcher in franchise history with a four-hit, two-homer day, joining Kenji Johjima in 2006.

“I wanted to finish the first half strong,” Narvaez said. “I’m pretty happy with what I’ve been doing. I’ve been hitting for power and for average. That’s tough to do.”

But the Mariners dug themselves an early hole when Carasiti allowed five runs (four earned) on four hits and one walk, while retiring just one batter in the first. The rookie right-hander had allowed just one run in four prior opener opportunities.

Seattle has now used the opener strategy 12 times this season with five relievers combining to post a 15.68 ERA with 20 hits, 13 walks and four home runs in 10 1/3 innings. The Mariners are 5-7 in those games.

Wade LeBlanc followed Carasiti and gave up just three hits and one run in 6 2/3 innings, but the Mariners couldn’t overcome a 6-0 deficit after the lefty allowed a second inning homer to Marcus Semien.

LeBlanc and Tommy Milone, the two starters who have been used to follow the openers, have combined for a 3.07 ERA in 67 1/3 innings in the 12 games.

“It’s nice when you can go out there and throw up a zero early, but we’ve had struggles doing that,” Servais said of the opener strategy. “It has helped the bulk guys, there’s no question. Their numbers dictate that as well. They’re able to get deep in ballgames and keep us right in the game, but it’s tough when you get behind the eight-ball right away.

“It’s something we’ll continue to look at as we go into the second half. Today, you get five early, our guys didn’t quit, but it’s tough to battle back.”