Luis Severino joined the six-inning club Wednesday, but it wasnt easy. Throughout the afternoon the veteran right-hander put plenty of traffic on the bases, with three walks as a factor. But the Mets, turning three double plays, gave Severino a boost. Luis Severino pitched six innings in the Mets win over the Pirates on Wednesday. Jason Szenes for the NY Post And so, for only the fourth time this season, the Mets had a starting pitcher complete six innings. They also completed a three-game sweep of the Pirates with a 9-1 victory at Citi Field. The Mets (10-8) won their fourth straight overall and departed for California for six games against the Dodgers and Giants as a team executing on all fronts. Mets starter Luis Severino pitching against the Pirates on Wednesday. Jason Szenes for the NY Post Severino was charged with only an unearned run over his six innings, in which he allowed five hits and struck out four. Jose Butto (twice) and Sean Manaea provided the Mets with the other starts of at least six innings. We mixed some two-seamers in there to get some double plays and I think that helped, Severino said. For Severino, who lowered his ERA to 2.14, it was a third straight start of allowing one earned run or le s. On this day he got the Wes Iwundu Jersey win his first in a Mets uniform. Explore More Severino, pitching to contact, averaged 96.3 mph with his four-seam fastball and got only three swings and mi ses with the pitch. Today, even though he went out for that sixth inning with 85 pitches I felt comfortable because the [velocity] was there, manager Carlos Mendoza said. Its important that the starters give us some length because its a long season and we have to protect some guys out there in the bullpen. Starling Marte (6) is greeted by Mets teammates after hitting a home run on Wednesday. Jason Szenes for the NY Post Starling Marte and Harrison Bader provided the offensive fireworks, each with a two-run homer. The sweep was the Mets first since July 4-6 of last season in Arizona. The Pirates arrived in Queens as a hot team, with 11 victories in 16 games to begin the season, but got steamrolled 18-5 in the series. Were doing great, Severino said. Were scoring a lot of runs and the defense was unbelievable today, we turned three double plays, so I think we are where we want to be. Francisco Alvarezs catchers interference helped the Pirates score an unearned run in the third to take a 1-0 lead. Mets center fielder Harrison Bader (r.) celebrates his home run with Pete Alonso (l.) on Wednesday. Jason Szenes for the NY Post Henry Davis hit Alvarezs left hand with his swing and was awarded first base before Alika Williams singled. Severino got Oneil Cruz to hit into a double play, but Bryan Reynolds ensuing infield single brought in the run. Severino encountered further danger in the inning with an errant pickoff throw that allowed Reynolds to reach second and walked Connor Joe before retiring Rowdy Tellez to escape. Martes two-run homer in the bottom of the inning gave the Mets a 2-1 lead. The Mets celebrate their win over the Pirates on Wednesday. JASON SZENES FOR THE NEW YORK POST Zack Short drew a leadoff walk against Bailey Falter in the inning and, with one out, Marte cleared the fence in left-center for career homer No. 150. Severino escaped trouble in the fifth by getting a third double play of the afternoon turned behind him. After Cruz singled and Reynolds walked, Joe hit a grounder to third that became an inning-ender. The Pirates werent retired in order by Severino until the sixth, when Tellez, Edward Olivares and Jack Suwinski were easily handled in an 11-pitch inning. Baders first homer in a Mets uniform, a two-run blast against Hunter Stratton, highlighted a sixth inning in which the Mets scored four runs to build a 6-1 lead. Tyrone Taylor delivered a two-run single before Bader crushed a shot into the left-field seats. Bader had go-ahead hits for the Mets in victories Sunday and Monday. Pete Alonso scores on a fielders choice hit by New York Mets catcher Francisco Alvarez during the eighth inning. JASON SZENES FOR THE NEW YORK POST Alvarezs RBI fielders choice in the eighth and Brandon Nimmos two-run double accounted for the Mets final scoring. We have a great group in here and its been fun, Taylor said. We are having a fun time playing for each other and I think that creates a winning mentality and its been cool to see us get some wins lately. Josh Green Jersey