Although Shawn Porter plans to walk through Paulie Malignaggi during the April 19 defense of his IBF 147-pound belt, just as he claims to have done in winning the title from southpaw Devon Alexander in December, he nevertheless admits Malignaggi could represent his "biggest test" since Julio Diaz.

The 26-year-old Porter (23-0-1, 14 knockouts) will face the 33-year-old Malignaggi (33-5, 7 KOs) in the Showtime-televised support of the 175-pound title unification bout between the IBF's Bernard Hopkins and the WBA's Beibut Shumenov at the D.C. Armory in Washington, D.C. The event will also include Peter Quillin's third defense of his WBO middleweight title against Lukas Konecny.

Porter's victory over Alexander left the ex-titlist bleeding from cuts over his eyes, ending Alexander’s winning streak at four consecutive bouts since falling to Tim Bradley, the current WBO 147-pound beltholder.

A former junior middleweight managed and trained by his father, Kenny, Porter’s victory over Alexander was preceeded by last September’s unanimous decision over ex-beltholder Diaz, with whom Porter had battled to a draw in December 2012.

"I can't forget those Julio Diaz fights. Both of those fights were great fights against Julio and he really tested me in ways that I had never been tested before on either the amateur or professional levels," said Porter.

"So I think that I'm coming into the ring against Paulie in about the same situation. They have both accomplished pretty much the same things, if not very similar things during their careers. So I would say that at this point that, yes, this could be my next biggest test to date up there with the fights against Julio."

In between the fights with Porter, Diaz, 34, dropped Amir Khan during the fourth round of a unanimous decision loss in April 2013. Diaz was looking for the one-punch knockout during the rematch with Porter.

"It was great for me to fight Diaz twice. Obviously, you don't want a draw but it helped us to regroup and to go over and to discuss some of the things the things that we did in the first fight. Coming into the second fight, I don't think that the timing was necessarily for us, measuring how much we had gotten or how much we had improved," said Porter.

"But the number one thing was to beat him and to be able to beat him decisively. I do think that after the fight, that was really when we were able to take a look at it. We were able to go over what we did. We were able to say that in the last fight, we did this and then we did that. We were able to say that this was good and that wasn't and to make improvements that way. So that was a great steppingstone for me to be able to gauge where I'm at and where I'm going."

Malignaggi unanimously decisioned Zab Judah in December, rebounding after losing the WBA title to Adrien Broner via split decision last June.

But Kenny Porter expects Malignaggi to be business as usual.

"If anybody is building this fight up to be anything bigger or better than it is, then they don't know what they're talking about. Everybody says that they're going to do this and they're going to do that until they get into the ring with us," said the elder Porter.

"It works both ways.We're not looking at him like he's just Paulie Malignaggi. We're approaching this guy like he's 6-foot-6 and weighs a thousand pounds. We're really prepared, even more than we were for Devon Alexander, so we're really going after this guy."