Hawn (18-2), a Tri Star fighter out of Dracut, Mass., lost a lightweight title fight to Michael Chandler a year ago. But as a late injury replacement in the season nine 170-pound tourney, Hawn rolled to three straight wins, including a nasty knockout of Ron Keslar in the finals.
"It's great to be back in title contention and going for that belt," Hawn said. "There is no question Douglas is an incredibly gifted fighter. In terms of his size and skill, this will probably be the toughest fight of my career, and I'm ready for that. I know how exciting this fight is going to be, and I'm just ready for April 18 to get here."
Lima (25-5), meanwhile, is also getting his second shot at a Bellator championship. The Brazilian lost a decision to then-champion Askren two years ago, but has since won four in a row, including a head-kick KO of Ben Saunders to claim the season eight crown.
"This fight with Hawn is going to be very explosive, I think everyone is aware of that," Lima said. "I really can't describe how excited I am for this world title shot. I'm bringing this belt home, and it's not leaving me for a long time."
The belt was vacated when Bellator did not renew Askren's contract.
"Lima vs. Hawn is just a fight fans dream come true," Bellator CEO Bjorn Rebney said. "Both of these are incredibly exciting to watch in the cage, and to have both of them set for a five round battle for our welterweight title is something I'm couldn't be happier about."