By Carlos Arias

LOS ANGELES --- IBF welterweight champion Shawn Porter is the hot fighter in the 147-pound division, but many ringside observers believe Julio Diaz deserved the verdict when they met in 2012.

Porter won a clear-cut decision over Diaz, who faces Keith Thurman for the interim WBA welterweight title on Saturday at StubHub Center in Carson on Showtime, in the rematch last September.

"The first fight with Porter I thought I won it," said Diaz at Westside Boxing Club. "The second time I fell into a whole different game plan and he outpointed me. But still they were both competitive fights against an undefeated fighter as talented as he is. And now look at the damage he's been doing. He's a world champion. What does that say about me?"

Porter went on to win a unanimous decision over Devon Alexander to claim the IBF welterweight title and he made his first title defense with a four-round destruction of Paulie Malignaggi this past weekend.

"I'm very confident my fights, especially the first one, helped him a lot more," Diaz said of Porter. "After that I seen him grow. Once he passed that test that I brought to him he became a better fighter. Right now, you can tell even more his confidence. He just destroyed Paulie Malignaggi. As a fighter that does something to you. Shawn Porter is going to go very far because his confidence is growing and the more he grows the better he gets."

Follow Carlos Arias on Twitter @PunchyMcGee.