According to Bob Wirz (IndyBaseballChatter.com and Wirzandassociates.com), there have been only two instances in pro baseball where a player hit a home run on five consecutive at-bats:
A few days ago, Cristian Guerrero hit five home runs in a Northern League game… and almost had a sixth!
In addition, over the course of a doubleheader in 1996, Corey Parker of the Bangor Blue Ox (Northeast League) hit 5 home runs over a doubleheader – three in his last three at-bats of the first game and two in his first two at-bats in the second game. Here are Corey’s stats from his pro career: http://www.baseball-reference.com/minors/player.cgi?id=parker001cor
There are several good books about the independent professional baseball leagues. You are welcome to see a list of suggestions through this link: Books Get notified of upcoming independent baseball tryouts from either of these services: first service or the second service. Prospective players can find some helpful resources here We will be providing a growing list of possibly helpful tips and suggestions on various baseball information. This will range from "how to" information about baseball skills all the way to helpful information for casual baseball fans. Please click the link for more information: Tips And How To Information