Jonathan Di Bella's respect for reigning ONE lightweight Muay Thai world champion Regian Eersel has reached new heights after experiencing the Dutch-Surinamese's skills firsthand during their training sessions in New York.The 29-year-old had long known why the Sityodtong Amsterdam fighter carries the nickname ‘The Immortal’, having watched him dominate the promotion’s lightweight striking divisions for years.However, their face-to-face training encounters provided a completely different perspective on the technical excellence that has made the 32-year-old the very best there is in the weight class.During his interview with ONE Championship, the ONE interim strawweight kickboxing world champion reflected on the reality of training with such elite-level competition while acknowledging how different it feels to experience Eersel's striking chops on the mats."I knew the skill level was there. But, like in front of me, when he's standing in front of me, it's real, you know? You can tell he's really good," Jonathan Di Bella told ONE Championship.The Dutch-Suriname destroyer was most recently seen in the main event of ONE Fight Night 34 last month. Eersel put English challenger George Jarvis to sleep in the opening round, just days before he flew out to 'The Big Apple' to work alongside Di Bella.As for the Team Di Bella Kickboxing star, he claimed the division's interim crown against the legendary Sam-A Gaiyanghadao at ONE 172 in March.He will attempt to unify his title in a rematch against two-sport king Prajanchai PK Saenchai in the main event of ONE Fight Night 36 in Bangkok on Friday, Oct. 3. View this post on Instagram Instagram PostPrajanchai points out the lone flaw in Jonathan Di Bella's arsenalHaving experienced Jonathan Di Bella's technical mastery firsthand, Prajanchai is well aware of what his nemesis brings to the table in their rematch.However, based on the Canadian-Italian's interim world title win over Sam-A in Saitama, the PK Saenchai man concludes that Di Bella still lacks one thing that makes him a completely dangerous opponent."I think the game plan [against Sam-A] was really fully created. I think the game plan was perfect. But I think he still needs to have that knockout power to finish up [his fights]," the reigning ONE strawweight Muay Thai and kickboxing world champion offered.