A chance to outdo Tyson Fury? Anthony Joshua set for Francis Ngannou showdown in Saudi Arabia
Joshua has faced intense scrutiny since a shock defeat by Andy Ruiz Jr in 2019, but the Olympic gold medallist is riding high on a three-fight winning streak.
Although wins against Jermaine Franklin and Robert Helenius in 2023 were solid if not spectacular, Hearn believes Joshua "found his aggressive streak again" against Wallin.
In the build-up, Wallin boarded the Joshua-bashing train by saying he was mentally weak and past his prime.
"It's how I felt," Wallin says of the comments, but he may have stoked a fire in Joshua. After five gruelling rounds, Wallin was pulled out by his corner.
"I felt like he was doubting himself and he wasn't really that confident or the killer he used to be," Wallin says.
"He took me by surprise. He came out pretty hard in the fight. He showed all the things I said weren't right."
Wallin was the first opponent Joshua stopped in the opening six rounds of a fight since 2016.
With a long-awaited Fury fight still on the agenda, Hearn feels Joshua is also winning back the support he craves.
"He had that for so long but one defeat against Andy Ruiz and people started questioning everything he'd done previously," Hearn says. "That hurt him. It definitely took its toll on Joshua.
"He looked sensational against Wallin and since then the narrative has changed considerably with people going 'blimey, I think he can beat Fury'."