Chandler retained his title on Jan. 17 with a second-round submission of Rick Hawn. The victory extended his unbeaten professional record to 11-0.
"I'm excited to get back in the cage and defend the belt against a tough guy like Jansen," Chandler said. "He's proven to be a very tough and durable competitor. My plan is the same as every fight, which is to show up new and improved and collect another dominant fight for the fans."
Jansen (19-2) will carry a six-fight win streak into the bout. In his most recent outing, on March 21, he defeated Marcin Held by unanimous decision.
The lightweight title fight headlines a card that kicks off a four-man light heavyweight tournament.
Petruzelli also looks to erase a recent loss -- a first-round TKO to Jacob Noe in January.
"Seth has been in this game for a long time and has beaten guys like Kimbo [Slice], Ricco Rodriguez and Dan Severn, so this fight is going to be tough. But I've been working my ass off in the gym with Jeff Mayweather and my team, and I'm ready to get another win under my belt," Lawal said. "Point blank, I'm looking to deliver a straight 'Mortal Kombat'-style fatality to Seth."
Veteran Renato "Babalu" Sobral takes on Noe in the other light heavyweight tournament bout.