With a mighty blast into Yankee Stadi um’s Monument Park, Alex Rodri guez yesterday joined one of baseball’s most exclusive clubs, hitting his 600th career home run — the youngest player ever to do so.

Only six other major-leaguers have belted as many as 600 round-trippers, a list that includes such immortals as Hank Aaron, Babe Ruth and Willie Mays, along with Barry Bonds, Ken Griffey Jr. and Sammy Sosa.

A-Rod’s landmark homer, off Blue Jays hurler Shaun Marcum in the first inning of yesterday’s game, came just one week after his 35th birthday — making him a full year-and-a-half younger than the Bambino was when he hit No. 600.

Of course, it’s disappointing that three of those in the 600-homer pantheon — including A-Rod — have either admitted, or been linked to, the use of performance-enhancing drugs.

That, sadly, was the nature of the game for far too long — and it makes the achievements of pre-steroid champions that much more impressive.

Still, Rodriguez deserves his cheers.

And the hope that he continues to set many more records in Yankee pinstripes.