There was so much talk about frustration and losing and bouncing back in every corner of the Mets’ world before they took the national stage last night against the Braves. But there was one other talk and it came in a dugout huddle with general manager Sandy Alderson, manager Terry Collins, COO Jeff Wilpon and Ike Davis. It was all about having fun again. By the end of the night, fun reigned. “ ‘Just have fun,’ that was the whole point of the meeting,” Davis said of the little huddle in the dugout, which was caught by the TV cameras. “Play like you used to, enjoy it instead. When you live two weeks or three weeks of straight negativity, you start to lose that glint of happiness, that little sparkle in your eye.” Davis, who snapped a hideous 0-of-17 streak the previous night, capped a three-run, eighth inning rally by driving in two runs with a bases-loaded single to right and the Mets found the winning formula after five straight defeats — and eight losses at home — in a 4-2 victory over the Braves. “Today was fun. So 1-for-1 on the new approach of having fun,” Davis, who also singled in walked in three previous at-bats, said with a smile. There wasn’t a single word, thought or idea about sending Davis to the minors after the Mets prepped for the upcoming Subway Series with the victory. “A couple guys said he looked more relaxed the last two games,” Collins said, recalling his thoughts when Davis, who ended an 0-of-26 slump with men in scoring position, stepped to the plate with the bases loaded against Braves reliever Cory Gearin (1-1). “I said if anybody’s watching, this kid needs to get a hit and he got it. We needed this game bad.” About as badly as Davis needed his mental-health game-winner. The heroics might not have been possible if not for an outstanding effort by starter Shaun Marcum who got a no-decision despite seven masterful, four-hit innings laced with a career-high 12 strikeouts. His only real blemish was a two-run Dan Uggla homer in the seventh that vaulted the Braves to a 2-1 lead and negated Lucas Duda’s solo homer for the Mets in the fourth off Braves starter Julio Teheran.