ST. PETERSBURG — Edwin Diaz took the Tropicana Field mound in the bottom of the ninth without having blown a save in nearly two years. After retiring two hitters in quick order, the unthinkable happened. He gave up a game-tying home run to Randy Arozarena, blowing a save for the first time since May 25, 2022. The Mets went up in the top of the 10th, only to fall in the bottom of the inning when left-hander Jake Diekman gave up a triple to Jonny DeLuca with runners on the corners (including the automatic runner) and none out. The Rays walked off with a 7-6 win to sweep the Mets. “I missed,” Diaz said of the full-count slider he threw to Arozarena. “I was trying to throw a slider down and away. I know he was struggling, so I wanted to make a good pitch to see if he could chase.” There is plenty of blame to go around beyond Diaz for the loss. The Mets led 5-4 for most of the game and had plenty of opportunities to pad the lead but the big hit never came. They left 13 men on base and went 4-for-16 with runners in scoring position. “Tough one,” said manager Carlos Mendoza. “Felt like we had opportunities and we just couldn’t come through offensively. I thought our bullpen kept us in games and guys battled. Just got to turn the page and get ready for the [St. Louis] Cardinals series now.” The Mets lead the league in walks allowed (155) and stolen bases allowed (52). These two went hand-in-hand Sunday when the Rays took every opportunity they could to run, and the Mets gave them plenty of opportunities to do so, walking nine hitters. The Rays stole seven bases in eight attempts (3-for-3 on Omar Narvaez, 4-for-5 on Tomas Nido), with Jose Caballero swiping four bags alone, including one in the 10th as the automatic runner. He stole third, allowing him to easily come home on DeLuca’s triple. “We’ve got to be better,” Mendoza said. “I know Narvy is having a hard time right now, but he’s also put in a lot of work. I thought our pitchers were a lot better today with times to the plate. We just couldn’t couldn’t do much about it.” Narvaez has not thrown out a single baserunner this season. Some of the blame can be placed on the pitchers as well, but the situation is becoming untenable with the backstop having allowed 30 stolen bases this season. The 32-year-old has been working on his pop times and throws to all three bases, but he’s at a loss for why he can’t curtail the running game and says the concern level is “high.” “There’s not much to say,” Narvaez said. “We’re facing a running team. It’s part of our game plan to hold the runners, but once again, they’re a running team. They know when to run.” Francisco Lindor hit his sixth home run of the year and Brandon Nimmo reached base five times, going 1-for-3 with an RBI single, a walk, two hit-by-pitches and an error in the top of the 10th that scored the automatic runner. But the rest of the Mets core wasn’t able to do much against seven Rays pitchers. Tampa Bay right-hander Ryan Pepiot left the game in the third inning after taking a come-backer off of his leg and the Rays pieced it together using the bullpen the rest of the way. Luis Severino labored through five innings and failed to establish his fastball command. He made it through five innings, which the bullpen needed, exiting with a 5-4 lead intact. Severino walked six hitters — the most of his career — and hit one. “I was trying to overthrow maybe,” he said. “When I don’t have that fastball command down and away, that’s a problem. Then the last couple of evenings I used more sinkers and changeups than anything else.” Severino managed to get out of trouble when needed and got plenty of help from the defense. The damage was limited to four earned runs on four hits, with six strikeouts, but some of the walks proved costly. The Mets (16-18) spotted Severino a 2-0 lead after Lindor homered off Pepiot in the first inning. Down 3-2 after Severino allowed three runs in the second, Starling Marte hit Pepiot with a come-backer to load the bases. The right-hander exited the game with a lower-leg contusion and was replaced by Manuel Rodriguez, who got two outs before walking DJ Stewart. Tampa Bay (17-18) went up 4-2 in the bottom of the inning. The Mets capitalized on poor defense by the Rays to take the lead in the fourth. The bullpen bent, but didn’t break. It was all set up perfectly for the best closer in the game to come in and shut the door, but too many mistakes and empty at-bats left them with little margin for error. Diaz made an error in his execution of the slider. The Mets have gone 4-10 since their six-game winning streak came to an end in Los Angeles. They departed Tampa for St. Louis following the game for a three-game series against the Cardinals. “We lost three games here, but that’s part of the game,” Diaz said. “Tomorrow is a new day.”