Cops arrested the man who fatally stabbed an aspiring Marine just hours before his 20th birthday, police said.

Wilson Rivera, 19, stabbed D’Anthony McDonald in the chest at about 9 p.m. on June 14 in South Ozone Park, cops said.

Rivera was charged with murder and criminal possession of a weapon, cops said.

It’s unclear what sparked the violence between the two young men, who lived just blocks from each other.