Pedro Florimon #23 of the Pittsburgh Pirates advances to third...

Pedro Florimon #23 of the Pittsburgh Pirates advances to third base in the seventh inning as a ball thrown for an error by Bobby Parnell #39 of the New York Mets (not pictured) gets by Ruben Tejada #11 at Citi Field on Sunday, Aug. 16, 2015. Credit: Jim McIsaac

The boos that rained down on reliever Bobby Parnell were considerably stronger than the showers that had halted play during the sixth inning Sunday at Citi Field. Somebody had to pay for what would become the Mets' third straight loss to the Pirates.

Turns out that Parnell, who endured a similar fan reaction as the losing pitcher Friday night, was a convenient target, but perhaps the wrong one this time, in the 8-1 loss.

The score was tied at 1 until the seventh. Starter Matt Harvey did not return after a 42-minute rain delay in the bottom of the sixth.

After Parnell walked leadoff batter Pedro Florimon, pinch hitter Michael Morse grounded a potential double-play ball to Parnell, who fielded it cleanly and threw to second base. The ball went over the bag and past the glove of shortstop Ruben Tejada and second baseman Daniel Murphy, who was screened by Tejada. Florimon went to third.

"You go from thinking you have two out, to first and third and none out,'' Murphy said. "And that's a good club there and they made us pay for it.''

The Mets, and Parnell in particular, paid heavily as the Pirates scored four runs in the inning. Gregory Polanco singled in the go-ahead run and another scored on a passed ball by Travis d'Arnaud. Aramis Ramirez singled in the third run of the inning and Parnell was removed amid thunderous boos from those who remained from a crowd of 40,250. Eric O'Flaherty then gave up an RBI single by Pedro Alvarez, who had homered off Harvey in the second.

Terry Collins quickly exonerated Parnell and went on a bit of a diatribe in the process. "The guy who was covering has got to be there,'' he said. "End of story. That's all. I didn't see the replay. I heard the throw was OK.

"You know what, we try to put our guys in defensive situations, defensive positions depending on who's pitching. If you can't get there, you've got to move. You've got to be able to get there. So Bobby got the double-play ball he needed to have. We didn't make the play.

"The part that gets me sometimes, we've always got to point a finger at somebody. It's always somebody's fault. Sometimes it's not just one guy. It just happens. It's part of the game. We didn't make the play. But I'm not going to lump it on one guy's shoulders that he was two steps over too far, the throw was too fast.

"Everybody's sitting around the bench listening to guys talk. 'Well, he should have been closer to the bag.' Make the play. It's the big leagues.''

Parnell left the clubhouse quickly, but Tejada remained and took responsibility. "I'm late to the ball, that's the only thing,'' he said. "He did what he has to do, catch the ball and make a good throw. He threw the ball right to the bag, so nothing on him. Everything's on me.''

The Mets remained 41/2 games ahead of the second-place Nationals, who were swept in four games by the Giants and have lost six straight.

Collins decided that even if it was a lost weekend, his team, which went 4-3 on the homestand, still is in good shape. Despite losing three in a row, the Mets lost no ground.

"If you would have told me on May 15 that with 44 games left in the season, we'd have a 41/2-game lead, I'd take it,'' Collins said. "As bad as this game ended up looking, I'll take it. We'll take the [day off Monday] and we'll come out in Baltimore ready to play."