Manny Pacquiao has laid down the gauntlet to Floyd Mayweather to make a return to the ring for a rematch of their 2015 clash after the Filipino took the Welterweight title belt against Lucas Matthysse.

On Sunday, Pacquiao scored his first knockout since his 2009 TKO of Miguel Cotto and he is already contemplating who he will fight next.

The obvious fight is a rematch with Mayweather, whom he lost to due to a unanimous decision three years in Las Vegas. Mayweather has not fought since his lucrative clash with UFC's Conor McGregor but the fact he was lured out of retirement for that mega-fight, Pacquiao has left the door open should he feel similarly.

"Mayweather? If he decides to go back to boxing then that is the time we are going to call the shots," he told reporters after his victory. "I have the belt, so it's up to him. If he wants to come back in boxing let's do a second one."

One thing is for certain is that he wants to defend his title. He is adamant that despite being 39, he feels 27 and the training which he endured for the Matthysse fight will stand to him.

Another opponent is Amir Khan who made his return to the ring in a 39 second knockout of Phil Lo Greco and Vasyl Lomachenko, who is almost 10 years his junior.

"Yes that's a potential opponent; Amir Khan. There's a lot of potential opponents there, like Lomachenko, there are so many fighters that have potential to be my opponent next."