Juan Nicasio retired his first 12 batters and got his second win in six starts, and the Pirates beat the Mets 3-1 on Tuesday night to complete a doubleheader sweep.
The Pirates also won the first game 3-1 behind seven scoreless innings from Jon Niese against his former team. Josh Harrison had three hits and Jordy Mercer hit his first home run at PNC Park since Aug. 31, 2014 in the first victory.
Nicasio (5-4) allowed a run on three hits and two walks over five innings. He had gone 1-2 with a 6.23 ERA in his previous five starts, and manager Clint Hurdle acknowledged last week that he was considering moving the right-hander to the bullpen.
Jacob deGrom (3-2) is winless in his last seven starts after he allowed three runs in six innings with nine strikeouts and no walks in the second game. He has not won since April 30 against San Francisco despite allowing three earned runs or fewer six times.
The Pirates had lost five of six prior to the twinbill sweep — the doubleheader was necessitated because of a rainout on Monday night.
The Mets have lost seven of their last 10 games and scored just 24 runs in that span. They are missing third baseman David Wright, first baseman Lucas Duda and catcher Travis d'Arnaud because of injuries.
John Jaso, Jordy Mercer, Sean Rodriguez and Chris Stewart had two hits each in the nightcap for the Pirates, who opened the scoring with a pair of runs in the second inning.
Mark Melancon pitched a perfect ninth, duplicating his first-game performance, for his 19th save in 20 opportunities.
In the opener, Niese (6-2) gave up four hits, walked two and struck out two. The lefty is 3-0 with a 1.74 ERA in his last five starts.
He was drafted by the Mets in 2005 and spent his entire career in the organization, including eight seasons in the major leagues, before being traded to the Pirates on Dec. 9 for Neil Walker.
"It was a little weird because It's the only organization I knew," Niese said. "All those guys are great over there. I got along with all of them. I definitely miss them, but I'm enjoying my time here, too. I had a good game plan going on. I tried to live at the bottom of the strike zone."
The Pirates snapped left-hander Steven Matz's seven-game winning streak.
Matz (7-2) allowed two runs and eight hits in five innings while losing for the first time since his season debut April 11 against the Miami Marlins. He struck out eight and walked two while losing on the road for the first time in nine career starts.
"He didn't command his fastball and you've got to command your fastball to make it work," Mets manager Terry Collins said. "He was up in the zone, up in the zone. He couldn't get the fastball down."
Walker, a Pittsburgh native, was a combined 2 for 8 in his first time facing the Pirates. He was their first-round draft pick in 2004, made his major league debut in 2009 and spent the last six seasons as the starting second baseman.
Mets: CF Yoenis Cespedes started both games and went a combined 0 for 7. He sat out Saturday at Miami and was limited to a pinch-hitting appearance Sunday against the Marlins because of a sore hip.
Pirates: LF Starling Marte was removed for a pinch hitter in the seventh inning because of a bruised left ankle then sat out the second game. ... C Francisco Cervelli (bruised right foot) was back in the lineup after missing three straight games and David Freese (bruised right hand) started at first base after sitting out four games in a row. ... RHP Ryan Vogelsong rejoined the team a week after having surgery to repair facial fractures sustained May 23 when he was hit by a pitch from Colorado's Jordan Lyles.
Mets: RHP Noah Syndergaard (6-2, 1.91 ERA) will start Wednesday night in the finale of the three-game series. He is 4-0 with a 1.15 ERA in his last five starts.
Pirates: RHP Jameson Taillon will be called up from Triple-A Indianapolis to make his major league debut. He was the second overall pick in the 2010 draft but sat out the 2014 and 2015 seasons while recovering from Tommy John surgery and a sports hernia.