NEW YORK -- Mets second baseman Jeff McNeil found himself in the worst slump of his career. Entering Friday, he was 29-for-152 (.191) since May 1 and saw his season batting average dip to .213.

Perhaps McNeil’s game against the Astros on Friday night is a sign that the one-time batting champion will have a great second half. In fact, his three-run home run in the bottom of the sixth inning helped New York defeat the Astros, 7-2, at Citi Field in the series opener.

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The Mets have won four consecutive games and find themselves a game over .500 (40-39) for the first time since May 2, when they were 16-15.

“We are playing good baseball right now,” Mets manager Carlos Mendoza said. “The approach is one day at a time, one pitch at a time and one series at a time. I’m going to continue to say that. We still have ways to go, but I like … the way we are going about our business.”

The game was tied, 2-2, when the middle of the Mets’ order faced Astros right-hander Ronel Blanco in the bottom of the sixth inning. With one out, Pete Alonso swung at a 1-2 changeup and hit the ball over the left-center-field wall to give New York a one-run lead.

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Four batters later, the Mets had runners at the corners with two outs when McNeil came to the plate. He saw eight pitches from Blanco and worked the count to 2-2 before he hit a changeup over the right-field wall for a three-run homer. At first, McNeil didn’t think the ball would go over the fence. He thought it would land in the right-field corner for extra bases.

“Sometimes you need something like that to get going,” said McNeil, who had three hits to lift his batting average to .221. “It’s nice to have a hit under my belt. I just wanted to drive the run in. I put a good swing on it.”

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McNeil acknowledged his visible frustrations at the plate. If he popped up, for example, he would slam his bat to the ground. For a long time, he couldn’t pinpoint what the problems were.

But McNeil had recent conversations with Carlos Beltrán, a special assistant in the Mets’ front office; teammate J.D. Martinez; and hitting coaches Eric Chavez and Jeremy Barnes. McNeil believes he found his swing and it started with the two-game series this week against the Yankees. He is 5-for-12 in his past three games.

“We were kind of digging deep, trying to figure out what exactly it is,” McNeil said. “I’m a feel hitter. I need to have a good thought at the plate, kind of what I’m doing. I think I’ve finally found that right now. So I’m going to ride with it and, hopefully, keep doing it.”

No matter how bad it was for McNeil, Mendoza kept telling the media that McNeil was his starting second baseman. That was true even when Jose Iglesias got off to a great start while starting at second base during the month of June.

“He has been great with me. I’ve had a few conversations with him, just trying to get going,” McNeil said about Mendoza. “It has been a fantastic relationship. I know they have confidence in me.

“It has been kind of tough. I haven’t been in the best place. From here on out, I can play extremely good baseball, help this team to a lot of wins and, hopefully, a good postseason run.”

McNeil’s enthusiasm running around the bases during the home run against the Astros told the story. This may be the start of a great second half.

“He needed it,” Mendoza said. “I’ve been saying, I like the at-bats of late. And today, [he is] finally getting the results. Obviously, the three-run homer there, it was huge. Credit to him. He is fighting. To go out there today and have a night like that, he needed it. Good to see it.”