MLB

Posada has up-and-down night

BOSTON — Jorge Posada’s day began with a bang, quite literally: The Yankees’ veteran catcher connected with a Josh Beckett fastball that eased over the far part of the bat, crushed it on a rope down the right-field line where it ultimately crashed against the Pesky Pole for the Yankees’ first run of the season.

It was the fourth Opening Day homer of Posada’s career, tying the team record.

Posada’s night ended with a base hit up the middle in the ninth, his third hit of the day, giving the Yankees an extra batter of life and hope.

But it also included what turned out to be the pivotal play of the game, when he couldn’t handle a Damaso Marte pitch that sailed high with David Ortiz batting. The ball popped out of Posada’s mitt, rolled away, and allowed Kevin Youkilis to score the go-ahead — and, ultimately, winning — run.

Posada, whose compatibility with A.J. Burnett became something of a distracting sideshow last year during the postseason, may have been crossed up, and he simply may have been wary because of Marte’s wildness. The reliever already had wild-pitched Youkilis to third base and wound up walking Ortiz, the lefty swing he was brought in specifically to face, the only man he pitched to.

“Those things are going to happen,” Yankees manager Joe Girardi said. “But taken in the larger context of the game, we had a couple of leads and couldn’t protect them, and when that happens you’re in a position where one or two plays can turn the course of a ballgame.”

Before the game, Girardi reiterated that Posada will catch Burnett, especially early in the season when a significant number of off-days will allow him to play every game the first few weeks and still get his required rest each week.

mike.vaccaro@nypost.com