AT&T Park — Matt Moore couldn’t escape the fifth inning and the San Francisco Giants couldn’t escape their fifth loss in as many games, falling 8-2 to the New York Mets on Sunday afternoon.

The defeat capped the club’s weekend sweep at the hands of the Mets and continues the Giants precipitous free fall. Losers of 12 of 13 and 21 of 26, the Giants have now racked up 51 losses — most in the majors.

“For some reason the baseball gods, I mean, they’re really testing us here,” manager Bruce Bochy said.

With his latest dud — Moore let in five earned runs on seven hits in 4.1 innings of work — the left-hander’s ERA crept past six. Moore’s 6.04 marks stands as the fourth-worst among all qualified starters.

“I’m sitting on a six (ERA) right now with not a lot of wins and not a lot of team wins when I’m throwing the ball,” Moore said. “So it’s been enough for me. The last couple months it’s been nothing that I’m happy with. There’s a lot of room for growth and a lot of room for improvement.”

On a sunny afternoon at Third and King, Moore was in trouble from the jump. The lefty walked Curtis Granderson to lead off the game, with the Mets table-setter eventually coming around to score. Moore surrendered runs in four of the five frames he started.

Rene Rivera, who entered the day with three homers in 36 games, took Moore deep twice in the first four innings. The Mets backstop boomed a two-run shot in the second and connected on a solo drive in the fourth, producing the first multi-home run game of his career.

“I made some pretty big mistakes to Rene right there,” Moore said.

“There were some crucial spots there where I didn’t make pitches,” Moore added. “I could have kept my pitch count down. I could have gotten us out of the inning a lot quicker.”

Boch also said the pair of big flies doomed his starter.

“He gives up two home runs to him by making mistakes there. That’s what killed him, really,” Bochy said. “Just command, today. That was the issue, which is the issue with all pitchers normally, but I think especially with him.”

Bochy on Moore and the struggling offense: pic.twitter.com/LcRngzb7r4

— Karl Buscheck (@KarlBuscheck) June 26, 2017

No moment better epitomized the club’s offensive futility than Buster Posey’s at bat in the bottom of the sixth.

With no outs and runners at first and second, Bochy put his runners in motion to avoid a double play. Instead, Posey flared a soft liner behind the bag at first allowing Lucas Duda to catch the ball and flip it to second for an easy twin-killing.

“We’re getting guys out there.” Bochy said. “We’re not doing enough damage. We’ve talked about that. We had the bases loaded [twice] and I think we got one run out of it.”

Slater exits early

Gorkys Hernandez replaced Austin Slater in left field in the seventh. The team later announced that Slater is dealing with a tight right hip flexor. Bochy said the rookie will get an MRI.

Slater headed for an MRI, Bochy says pic.twitter.com/ynPWUdPV0h

— Karl Buscheck (@KarlBuscheck) June 26, 2017

Bumgarner takes the mound in Arizona

Recovering left-hander Madison Bumgarner was scheduled to throw three innings for the club’s Arizona rookie league team on Sunday nigth. The ace will rejoin the Giants at AT&T on Monday, throw a bullpen during the homestand and map out the rest of his rehab plan with Bochy.

Bochy targets Friday return for Núñez

Bochy is aiming to have Eduardo Núñez — out since June 19 with a left hamstring strain — back by Friday. The third baseman took ground balls on the field before Sunday’s game.Bruce Bochyeduardo nunezMadison BumgarnerMatt MooreMLBNew York MetsSan Francisco Giants