Khan stopped Malignaggi in the 11th round at Madison Square Garden
Amir Khan has vowed to unify the light-welterweight division after retaining his WBA title with an 11th-round victory over Paulie Malignaggi.
Khan, 23, enjoyed an impressive American debut with victory over New Yorker Malignaggi, who was outclassed throughout Saturday's fight.
"I'm making 140lb easy, I feel strong," Khan said following his victory.
"I'm not leaving 140lb until I unify the title. Until I'm number one I'm not going to leave this division."
For Khan, who has been tipped to step up in weight, it was the second defence of his WBA title, having beaten Dmitriy Salita in Newcastle last December.
"It's my first fight away from home so I'm very happy," added Bolton's Khan.
"He was an awkward opponent, but we stuck to the gameplan and stopped him in the 11th round.
"We had to break him down slowly, we didn't want to run in there trying to knock him out because we would have got caught with shots.
"I was a little nervous, I was fighting in his home town but I put in the hard work in the gym and I knew my work ethic would carry me home."
After beating Malignaggi, Khan said he was confident of defending his title again against mandatory challenger Marcos Maidana of Argentina.
I'll fight Maidana and if Devon Alexander and Timothy Bradley fight, like two semi-finals, then the winners can fight each other to see who is the number one
The big hitting Maidana boasts 27 wins from his 28 fights, with 26 stoppages and should provide a sterner test of the Bolton man's credentials.
And Khan is also targeting a unification fight against unbeaten WBO light-welterweight champion Timothy Bradley or unbeaten WBC and IBF light welterweight champion Devon Alexander.
"I want to meet the likes of Marcos Maidana, Timothy Bradley and Devon Alexander to unify the titles," said Khan.
"Maidana is a great fighter, but I know I can beat him.
"I'd like to fight him next and I feel I've made a statement with this win.
"I'll fight Maidana and if Devon Alexander and Timothy Bradley fight, like two semi-finals, then the winners can fight each other to see who is the number one."
Trainer Freddie Roach added: "The key factor was the jab and he showed a lot of composure and stuck to the gameplan."
And Malignaggi paid tribute to Khan, adding: "I don't know if I'm getting old, I'm 29, I didn't feel old.
"Amir just came and fought a very good fight, very busy, a lot of angles. He kept me at a distance.
"When I turned pro I had a very similar style to Amir and I ran into a clone of myself, he was stronger, bigger and faster.
"He was very busy, I couldn't keep up with him I guess, I couldn't get the distance right.
"He had that youthful enthusiasm, he stayed busy, he wanted it and I give him a lot of credit."