BALTIMORE — Before the Yankees arrived here on Sunday night, Aaron Boone was not overly interested in putting too much weight into their four-game series against the Orioles.

Just part of the long season, Boone insisted, a true (if cliche) statement that likely would have remained the message even if the Yankees had come into Camden Yards this week and aced their first test against the defending AL East champs.

Well, they were not quite up to snuff.

With a chance to salvage a split on Thursday, the Yankees played their worst all-around game of the series and fell to the Orioles 7-2, as they dropped three of four.

Carlos Rodon had his roughest start of the season and did not get much help behind him or from the Yankees’ bats.

After scoring 30 runs on 37 hits in their last two games entering this series, the Yankees (20-13) mustered just six runs on 22 hits across four games against the Orioles (20-11).

Rodon, who had been mostly sharp coming into Thursday, gave up plenty of loud contact across four-plus innings in which he allowed seven runs (six earned) on eight hits.

That included three solo home runs — after giving up three home runs combined in his first six starts — and then not making it out of a four-run fifth inning that blew the game open.

Adley Rutschmann led off the fifth with a double before Ryan Mountcastle singled him home to put the Orioles up 4-1.

Anthony Santander then hit a grounder up the middle that Anthony Volpe made a diving stop on, but his flip to second base was dropped by Gleyber Torres, who tried to barehand it.

Jordan Westburg followed with a triple to the gap that scored both runs for the 6-1 lead and knocked Rodon out of the game.

Torres later hit his first home run of the season in the sixth inning, a solo shot off lefty reliever Keegan Akin, that made it a 7-2 game.

The struggling Torres had gone his first 32 games of the season without going deep, though it was too little, too late on Thursday.