Bobby Parnell gave up two hits, had a throwing error and saw his ERA swell to 6.05, Michael Cuddyer seemed to forget to cover 1st as pitcher Eric O'Flaherty went to field a routine grounder and the Mets dropped the series finale to the Pirates, 8-1.
Travis d'Arnaud had the Mets only run with a solo shot in the bottom of the second inning. He also had two of the Mets four hits.
Pittsburgh's Jeff Locke struck out four and walked two over 5.1 innings.
Matt Harvey went six, struck out six and gave up seven hits on one run while the bullpen combined for eight hits.
There was a 41-minute rain delay in the sixth inning.
The Mets are off Monday and return to action against the Orioles in Baltimore on Tuesday night.