Before Jake Paul showed some big-time toughness in the ring vs. Mike Tyson on Friday ... he displayed his huge soft spot on Thursday -- sweetly hosting a boy who's battling cancer throughout some of his pre-fight festivities.
El Gallo's guest of honor was Owen Obey -- a 7-year-old who was diagnosed with bone cancer earlier this year -- and TMZ Sports has learned social media influencer Samuel Weidenhofer actually helped the two link up.
Obey's mom, Chelsi, tells us Weidenhofer learned of Owen's story weeks ago ... and was so moved by it, he asked Jake if he'd be interested in meeting the youngster during fight week this week.
After Jake gave the big green light, Weidenhofer went to work ... and, eventually, he got Owen and his family to hang with Paul in Dallas the day before the 27-year-old's big AT&T Stadium clash with Iron Mike.
Chelsi tells us ... Owen got to chill with Jake in his dressing room before his weigh-ins for the scrap -- and they chopped it up and took a bunch of pics.
At one point, Owen even got to share one of his bracelets with the fighter, who then wore it when he walked out onstage at the weigh-in spectacle.
Chelsi tells us after it all concluded ... her boy called it, "the best day of his life."
"And, he was so excited," she added.
Owen and his fam then got to go to the big fight Friday night too.
Owen still has a ways to go in his bout with his disease -- the family has actually set up a GoFundMe for those wishing to donate to his recovery efforts -- but it's clear he's got some powerful people now in his corner as he makes his steps forward.