Manny Acosta surrendered six hits and three runs in 1 1/3 innings, including a walk-off single to Clint Sammons, and the Mets lost to the Miami Marlins, 6-5, on Saturday afternoon in Jupiter.

The Mets fell to 7-18-2 in the Grapefruit League.

Josh Thole contributed an RBI triple and Mike Nickeas followed with a pinch-hit two-run homer in the fifth inning against left-hander Mark Buehrle as the Mets pulled even at 3. But the Mets could not hold an eventual two-run lead.

Earlier, Frank Francisco’s rocky spring continued. Signed to a two-year, $12 million deal to serve as closer, Francisco surrendered earned runs for the sixth time in 10 Grapefruit League appearances. He allowed two runs on five hits and a walk while working the third and fourth innings.

Francisco escaped further damage by striking out Buehrle and retiring Giancarlo Stanton on a pop-up to second base with the bases loaded in the latter frame. Stanton was playing only his second game since getting hit on the wrist by Chris Schwinden on March 11, then also publicly disclosing a knee issue.

“He’s one those veteran guys,” Terry Collins said about Francisco. “You know, I’ve had probably five or six people in the last week say, ‘Don’t get caught up in what he does in spring training. He does it every spring. He steps it up when the big lights come on.’”

• Miguel Batista started and limited the Marlins to a solo homer by Hanley Ramirez in two innings.

• Back in Port St. Lucie, Andres Torres felt good playing in a minor league game, according to Collins.

Torres, who is trying to return in time for Opening Day from a strained left calf, had reported feeling rusty in his first game action, the previous day. Collins said Torres will continue to work on the minor league side, to preserve the Mets’ ability to backdate into spring training any disabled list stint, if needed.

“He said he felt very good today,” Collins said. “He ran good. They said he hit two groundballs and ran very well to first base. Good signs. We’ll see what happens tomorrow.”