A Brooklyn cop accused of sodomizing a pot-smoking suspect with a retractable baton took the stand yesterday and admitted that he took the weapon out while giving chase — but flatly denied that it went anywhere near the man’s buttocks.

“I didn’t know what I was getting into. It was just for my safety,” Officer Richard Kern, 26, said of the Oct. 15, 2008, pursuit of Michael Mineo into the Prospect Park subway station.

Kern said he used the baton to hold Mineo’s legs down, but put it away to take out his handcuffs.

“Did you at any time shove, force or ram your ASP [the baton] into Mr. Mineo’s rear end?” defense lawyer John Patten asked.

“No, I did not,” swore Kern.

He’s accused of aggravated sexual abuse covered up by two fellow cops who issued Mineo a summons rather than take him into custody.