The Mets started Sunday afternoon by demoting struggling Jose Valverde from the closer’s role and pulling slumping Curtis Granderson out of the cleanup spot. They ended it with Valverde getting the decision and Granderson getting the deciding RBI, hoisted aloft by catcher Anthony Recker and mobbed by his teammates. No, Valverde’s win doesn’t mean he has turned a corner, and Granderson’s sacrifice fly won’t automatically end his funk or the fans’ boos. Nonetheless, the duo contributed to the Mets’ 4-3, 14-inning victory over Atlanta at Citi Field. “Baseball is crazy sometimes,’’ Valverde (1-0) said after pitching a scoreless 14th inning to earn the win. “That’s why you have to enjoy every moment.’’ That beleaguered pair authored a moment to enjoy. Yes, the Mets are still just 3-6 at home, but baby steps. This was one the 33,131 at Citi Field got to relish. “To get it that way, to help the team out was obviously a good thing,’’ said Granderson, 0-for-6 with an error — throwing the ball into the Atlanta dugout — and was lustily booed before delivering in extra innings. “You can’t help but hear it. I wasn’t giving them anything to cheer about. That’s to be expected when you’re not doing the things you need to do out there.’’ That’s an understatement. Granderson received a four-year, $60 million deal this offseason to be the Mets’ cleanup hitter. Instead, he struggled so mightily, manager Terry Collins moved him to the No. 2 spot. In the 14th, Kirk Nieuwenhuis drew a leadoff walk off reliever Gus Schlosser (0-1), and moved up on Ruben Tejada’s sacrifice bunt. The Braves intentionally walked .215 hitter Eric Young Jr. to face Granderson. The runners moved up on a wild pitch, then Granderson lifted a fly ball to left, Nieuwenhuis sliding home to beat Justin Upton’s throw. “I’m really happy for him. We don’t know what’s going to happen but you hope this is something that he can build on and move forward and get it going,’’ Collins said of Granderson, mired in an 0-for-16 skid and batting .127. “He just has to battle through some tough times, and he has the ability to do that.’’