Jesse Hart still works hard. But he is Jesse "Hard Work" Hart no more.

"After the lesson that I learned from Roberto Ramirez, my manager Steve Andrews said, 'We need a character change,'" said Hart. "We out with the old and in with the new."

That lesson from Ramirez was a painful one — a narrow but unanimous decision loss last September, spoiling Hart's undefeated record and costing him the WBO world super middleweight title. It prompted a total self re-evalution that trickled down even to the now-29-year-old Philadelphian's nickname.

That's how Jesse "Hollywood" Hart was born. And on Saturday night in Atlantic City, "Hollywood" Hart (24-1, 20 knockouts) will face his first real test since the rebranding.

Mike Gravronski (24-2-1, 15 knockouts), a wry Washington native with a reach six inches less than Hart but a record nearly as impressive, will be the challenger. Gavronski hasn't lost since 2015, but that came against Dashon Johnson, a fighter whom Hart stopped less than a year later and an example of what Hart described as a lack of resilience within Gavronski.

"He has a good jab, but as the rounds go on, he lacks confidence," said Hart of Gavronski. "I'm all around, I can do it all — I can go inside, I can go outside, I can do whatever you want me to do."

Hart is coming off two decisive victories earlier this year, knocking out Thomas Awimbono in the first round in January and then Demond Nicholson in the seventh round of an April fight.

Those victories have boosted Hart back up to No. 1 in the WBO's super middleweight rankings and No. 3 in the WBC's, and he said he's approaching this new title ascent — presuming he can survive Gavronski — with a new attitude following the Ramirez setback.

"The lesson I learned from that is to start early and to not get flustered and overwhelmed by the hype of the 'world championship,' that word," he said. "You've got to find a way to adapt and take yourself to a place in your own mind and … keep your composure."

Part of his plan to accomplish that is the new nickname, an indication of his shift to a more confident persona. Inspired by Floyd Mayweather's similar branding change in the 2000s — "All the great ones change their name," he explained — Hart said his "Hollywood" identity has already twice demonstrated the same flashiness that he plans to bring Saturday.

"When 'Hollywood Hart' came out, he had two knockouts," he said. "So it's like a rebirth, a fresh start."

Hart vs Gavronski

Where: Ovation Hall at Ocean Resort Casino, Atlantic City, N.J.

When: Saturday, 10 p.m.

How to Watch: ESPN