ST. PETERSBURG -- The Rays reached the midway point of their season in frustrating fashion on Wednesday afternoon.

Clinging to a one-run lead, manager Kevin Cash pulled a dominant Ryan Pepiot with one out in the sixth inning, and reliever Shawn Armstrong gave up a three-run homer to Cal Raleigh. The Rays put together a late rally, as usual, but couldn’t recover as they lost to the Mariners, 5-2, at Tropicana Field.

Had they swept the Mariners, the Rays would have moved above .500 for the first time in more than a month. They’ve seemingly created some momentum near the end of a remarkably inconsistent first half, winning three straight series, seven of their last 10 games and 10 of their last 15.

Instead, they fell back to 40-41 with exactly half of their regular-season schedule in the books.

“That's the most frustrating part for me today. We've been playing really good baseball. I didn't do my job today to keep us in the game,” Armstrong said. “Tough loss today, and that's on me.”

This is only the fourth time Tampa Bay has been below .500 through 81 games since dropping the “Devil” and becoming the Rays in 2008. They also had losing records after 81 games in 2014 (33-48), ‘16 (33-48) and ‘18 (40-41), all years they missed the postseason.

To return to the playoffs for a sixth consecutive season, the Rays know they can’t repeat what they’ve done to this point. For starters, they haven’t had a winning record since they were 25-24 entering play on May 21. They haven’t been more than three games above .500 all season, and it took a great week for them to dig out of a season-low hole five games below the break-even point.

“We've got to play better. The guys know that,” Cash said. “I feel like we've done some better things here as of late, so encouraged by that. But we set ourselves back a little bit. Now, we’ve got to make up for it in the second half and continue to play the way that we have. … Certainly like this team and what it’s capable of doing.”

The Rays liked the way Wednesday’s series finale started, too.

Yandy Díaz extended his hitting streak to 19 games (tying Jason Bartlett’s franchise record) with a first-inning single and his RBI streak to eight games (also tying a franchise record held by Rocco Baldelli, Carlos Peña, Ben Zobrist and Evan Longoria) thanks to some heads-up baserunning by José Caballero on Díaz’s third-inning grounder back to pitcher George Kirby.

Meanwhile, Pepiot struck out eight batters while allowing just one hit and a walk during his first two trips through the Mariners lineup. But he issued a one-out walk to J.P. Crawford in the sixth. That brought an end to his outing after 88 pitches, six shy of his season high, as Cash summoned Armstrong from the bullpen.

“I thought Pepiot threw the ball really, really well. Just felt like, with the top of the order getting turned over right there, the way Army is throwing the ball, that was the right decision to make,” Cash said. “It didn't play out that way, but that happens at times.”

“To be pulled when I was pulled, facing the lineup a third time, the heart of the lineup coming up, we have all the faith in Army,” Pepiot said. “Sometimes baseball is going to baseball. It just happened to go that way, not our way today.”

Armstrong induced a grounder from Josh Rojas for the second out. Up came Julio Rodríguez, who was 3-for-32 with a walk and nine strikeouts on Seattle’s road trip at that point. Armstrong got ahead of Seattle’s struggling star, 0-2, but eventually walked him on nine pitches.

Armstrong then fell behind Raleigh, 3-1, and misfired a fastball that Raleigh launched a Statcast-projected 422 feet with an exit velocity of 109.9 mph, just below the right-field scoreboard.

“I was just trying to go up and away, not middle down. That's his honey hole,” Armstrong said. “Bad pitch, good hitter. He did what he needed to do.”

The Mariners put up two more runs against reliever Kevin Kelly in the seventh, and Seattle reliever Trent Thornton limited the Rays to one run after closer Andrés Muñoz loaded the bases with nobody out in the ninth.

It wound up being the Rays’ 22nd loss of the season after holding a lead, third-most in the Majors behind the White Sox (28) and Rangers (23).

Eighty-one games down. Eighty-one -- and more, they hope -- to go.

“I know it’s been a tough season for us, but we have to keep the mind positive,” Díaz said through interpreter Manny Navarro. “And we have to keep that mind positive all the way until October.”