NEW YORK — When the A’s arrived to the visiting clubhouse inside Citi Field on Thursday morning, each player that walked through the entrance to their locker was greeted by a message on a giant whiteboard that read, ‘The only thing that matters: Win The Series.’

For about a month now, few teams have been better at doing just that than the A’s. After outlasting the Mets in a grueling 7-6 victory to take two of three from New York, Oakland clinched its seventh series win in its last nine tries.

At 3 hours and 45 minutes, the A’s series finale against the Mets was the the longest nine-inning game in the regular season under the pitch timer.

JJ Bleday sparked the comeback by cutting into a large chunk of a five-run deficit by launching his first career grand slam in the fourth inning off Mets starter Jose Quintana. The A’s tied it in the sixth on a groundout by Tyler Nevin and took the lead in the seventh on Seth Brown’s go-ahead RBI single.

The A’s bullpen picked up a short outing of 2 2/3 innings by rookie Mitch Spence. Four relievers combined to allow just one run in the final 6 1/3 innings, with flamethrowing All-Star closer Mason Miller closing things out with a scoreless two innings to notch his 18th save of the year.