NEW YORK — It was supposed to be a scripted question-and-answer session with Showtime commentator Jim Gray, but Philadelphia boxer Danny Garcia had a question of his own for opponent Shawn Porter.

"Have you ever been the underdog in any fight?" Garcia asked. Porter responded that he "most definitely" had been, and that he would even be the underdog in the duo's Sept. 8 fight at the Barclays Center in Brooklyn. Garcia quickly piped back: "You already put yourself the underdog — you already came to lose."

In a Monday news conference officially announcing the fight for the vacant World Boxing Council welterweight title, Garcia and Porter did little to smooth over their testy relations, which date to February. Back then, after Garcia (34-1) knocked out Brandon Rios — a rebound win for the 30-year-old boxer, who had lost his undefeated record in a controversial decision the previous August against Keith Thurman — Porter (28-2-1) leaped into the ring in Las Vegas and challenged Garcia on the spot.

Porter said Monday that it was the first time he'd personally picked his next opponent and took credit for "making this fight happen."

"Watching him do what he does and time after time saying, 'You can't do that to me; this is what I would do to you,' it stirred up to the point where I really wanted to fight Danny Garcia," said Porter, a Cleveland native. "His last fight, I saw an opportunity to really get that in front of everyone and make that be known worldwide. That's why, I think, we're here right now."

But Garcia disagreed, saying the fight came about simply because he and Porter are the top two contenders for the vacant world title. (If Garcia wins, it will be the fourth title of his career.) He repeatedly emphasized that Porter was "disrespecting" him and had been ever since February.

"I'm stronger than him. I've got bigger punching power than him. I'm faster than him. I'm a better all-around fighter than him," Garcia said.

Porter is known as a very aggressive, risk-taking, occasionally erratic fighter with a tendency to make bouts "crazy," and he said he would continue those strategies in the September matchup.

That will be a welcome tactic to fight against, Garcia said, because of its similarities to Rios' style.

"It was actually a perfect fight because he was aggressive, and now that I'm fighting Shawn, I'm training for the same kind of fighter again," Garcia said. "I'm already in that mind-set of fighting someone who comes forward."

The Philadelphian has been training for six weeks already, working on conditioning and pace-controlling skills that could prove crucial against a fighter of Porter's nature. But he added that if Porter opens up early, he'll see the opportunity for a quick knockout.

Comments such as that dominated the news conference, with neither fighter missing any opportunity to put down the other. Porter called Garcia less intelligent; Garcia said he would've "got hell" if he had taken as long to beat Adrian Granados, Porter's most recent opponent, as Porter did. On and on it went, in a never-ending dispute that will take another six weeks to resolve.

"At the end of the day, it wasn't the first time somebody called me out and it won't be the last," Garcia said. "Come Sept, 8, I have to be ready."