I mentioned a few days ago that Carl Yastrzemski hit no career homers off of Gaylord Perry. Campaneris hit three of of Perry in 78 plate appearances. Two more of his homers came of Gaylord's brother Jim.
He had three 2-homer games including his first two homers off of Jim Kaat. Not bad for a guy who averaged a homer every 121+ at-bats in his career.