In a day of unbelievable events, this might be the most mind-shattering of them all …

After Daniel Nava hit a grand slam on the very first major league pitch he ever saw, there have now been four players in big league history to claim home runs with the bases loaded in their initial major league game — Bill Duggleby (1898), Jeremy Hermida (’05) and Kevin Kouzmanoff (’06).

Of the group only Kouzmanoff and Nava hit their grand slams on the first big league offering they saw. Pretty good, right?

Well, Victor Martinez can top that.

The Red Sox catcher can claim to having not only been present for both of the historic first-pitch home runs, but he has also has proof that he predicted both would take place just prior to their completion.

Saturday, while sitting up in the Red Sox’ clubhouse during the second inning of what would be a 10-2 win over the Phillies, Martinez offered his prediction of Nava’s blast.

“He was standing right next to me when he said, ‘First pitch, bomb!’” said Red Sox DH David Ortiz. “I came up to get some batting gloves because of the rain and Vic was here. He said, ‘Watch this, first pitch grand salami’ There you go.”

But before you surmise that it was just a lucky guess, understand Martinez has a history with such things. That was thanks to Kouzmanoff’s first-pitch blast sat a member of the Cleveland Indians back on Sept. 2, 2006.

When he first got there I said, ‘If I was you I would swing at the first pitch.’ He said, ‘You think I should do that?’ I said, ‘Why not? You play in Double A and Triple A, but you haven’t played against the Rangers so those they probably didn’t have a good scouting report on you from the minor leagues. So if I was you i would swing at the first pitch.’ So guess what? First at-bat, bases loaded, off of Kevin Millwood — first-pitch grand slam.

“When he walked to the plate I called a grand slam.”

When asked if he had duplicated his effort this time around, Martinez resounded, “When you see David ask him.”

Hence, the Ortiz confirmation, and another legend to build on to Nava’s historic day.

“Unbelievable,” Ortiz said.