Dominik Mysterio Says SummerSlam Wasn't Best Performance, Still Getting Better

Dominik Mysterio is still WWE Intercontinental Champ after beating AJ Styles at SummerSlam on Sunday -- a match many fans say was his best ever -- but Dom disagrees, telling TMZ Sports he's only getting better!

We caught up with Dirty Dom out in NYC Monday morning ... and he tells us he did "absolutely nothing special" in training ahead of his title defense against the future WWE Hall of Famer.

"He had to prepare for me," Mysterio said. "It was my 20-year anniversary, so AJ had to prepare for what was coming for him, and that was Dirty Dom."

FYI, the 20-year anniversary remark refers to the infamous match between Eddie Guerrero and Rey Mysterio back in 2005 ... which saw custody of Dom on the line. Rey ended up winning.

Back to present day, Dom disagrees with the notion online that Sunday was the best match of his early career, saying he's only going to get better.

"I'm only five years in," Mysterio said. "This is only the beginning."

Despite father and son not being on the best of terms these days, in 2021, Rey told us that Dom would surpass him in the ring when their careers were all said and done.

"I truly believe in my heart, and I don't just say this so he can stamp it in his head, but he's gonna be better than his old man," Rey said.