NEW YORK -- The Miami Marlins weren't laughing when pitcher Henderson Alvarez extended the second inning Saturday afternoon by forgetting how many outs there were on a potential double-play grounder.
But Alvarez ensured the Marlins would be able to smile afterward by throwing seven shutout innings to lead Miami past the New York Mets 3-0 in the first game of a doubleheader at Citi Field.
"It's weird, can't be happening like that," said Marlins second baseman Donovan Solano, who scored Miami's first run in the fourth, hit a solo homer in the sixth and preserved the shutout with a defensive gem in the seventh inning. "But it's funny. The good thing is that (the Mets scored) no runs."
The mental gaffe by Alvarez, who allowed four hits and no walks while striking out five, provided the Mets with their biggest threat of the afternoon.
Lucas Duda led off the second with a single and Matt den Dekker singled one out later. Travis d'Arnaud followed with a comebacker to the mound, but Alvarez, thinking there were two outs, casually flipped the ball to first and started to walk off the mound before he saw catcher Koyle Hill, who was standing at home plate with his arms held out.
Alvarez then hit Omar Quintanilla with a pitch to load the bases and went to a full count with opposing pitcher Carlos Torres before he induced another comebacker to finally end the inning.
Alvarez allowed just two hits the rest of the way, but while the mental gaffe didn't cost him on the scoreboard, it might have cost him a shot at pursuing his second career shutout. Alvarez had to throw another 10 pitches after d'Arnaud's groundout.
"He just lost track of outs and really cost himself about (10) pitches," Marlins manager Mike Redmond said. "He might have been able to probably pitch into the eighth. I know that stuff does happen, but we've got to know how many outs there are."
The win was just the second for Alvarez (4-4) in his last eight starts. He entered Saturday with a 6.67 ERA over his previous six outings but tied a season high with the seven scoreless innings. He also threw seven shutout innings in a no-decision against the Brewers on July 21.
"Henderson Alvarez is real good," Mets manager Terry Collins said. "(The Marlins) have done a tremendous job of securing down good, young, talented, good-arm pitchers."
Chad Qualls threw a perfect eighth inning and Steve Cishek recorded his 30th save by working around a one-out walk and striking out the side in the ninth. He has converted 25 straight save opportunities.
The Marlins didn't get a hit off Torres until the fourth inning, when Logan Morrison's two-out bloop single brought home Solano, who led off the inning by getting hit by a pitch for the second time in as many at-bats.
Solano hit a home run to left field leading off the sixth to extend the Marlins' lead to 2-0. He then helped Alvarez escape the seventh inning when, with two outs and the Mets' Matt den Dekker on third, Solano made a sliding stop of Quintanilla's grounder and threw him out by a step.
"That play at second was unbelievable," Redmond said. "It came at exactly the right time, where we needed a big play. Saved us a run. In long days with doubleheaders, you need somebody to step up and be the hero. And today Alvarez and Solano gave us a big lift."
The Marlins (55-92), who won for just the third time in their last nine games, built their last run in the eighth when Christian Yelich doubled, stole third and scored on Morrison's groundout.
Morrison's line drive glanced off the right wrist of Mets pitcher Frank Francisco and bounced to first baseman Lucas Duda, who tagged out Morrison. Francisco, who missed the first 139 games while recovering from offseason elbow surgery, bent down in obvious pain and was helped from the field.
Yelich finished 2-for-3 with a pair of stolen bases.
Den Dekker had two hits for the Mets (65-82), who fell to 3-10 this month and clinched their fifth straight losing season.
Torres allowed two runs on three hits and two walks while striking out a career-high eight over six innings.
NOTES: The doubleheader was necessitated by a rainout on June 7. ... The Mets activated RHP Jeurys Familia from the 60-day disabled list prior to the doubleheader. To make room for him on the 40-man roster, they moved RHP Bobby Parnell to the 60-day disabled list. Familia, who underwent surgery to remove bone chips and loose bodies from his right elbow on June 5, hasn't pitched for the Mets since May 8. ... The Savannah Sand Gnats, the Mets' Single-A affiliate in the South Atlantic League, won the league championship series with a 2-0 win over Hagerstown in Game 4 of the best-of-five series on Friday night. ... The two-steal game was Yelich's first as a big-leaguer. ... Marlins RHP Sam Dyson will make his first major-league start in Monday's series opener against the Phillies.