Lee Selby was disappointed with his performance despite successfully defending his IBF featherweight title in Phoenix, Arizona.
The 28-year-old Welshman beat Mexico's Fernando Montiel, 36, with a unanimous points decision.
Selby was made to work hard for the win and suffered a cut above his right eye.
He said: "I am not happy, I can box a lot better. It was my first fight in America and I wanted to impress, but I did not perform as I thought I would."
The judges scored the bout 119-109, 118-110 and 116-112 to Selby.
He added: "It was hard to find my range and land cleanly on him due to his experience.
"I've got to take confidence from it. He's a top fighter so I've gained a lot of experience and dug deep when I had to."
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A tricky debut in America
Selby had wanted to put on a show in the United States because the fight was on free-to-air TV, as he bids to break into the lucrative market in America.
But he does not think his performance will have done much to help him win over the American public.
"I was not as impressive as I can be, but they got to see me and they will get familiar with my name," said Selby, who has lost just once in 23 fights.
"Next time I come out here I will put on a show for them."
Selby and his pregnant girlfriend had been considering naming their baby Phoenix, on the proviso the Barry boxer won in the American city.
However, he said: "If I had put in a good performance and sparked him out, then maybe I would have called her Phoenix, but not now."
Promoter Eddie Hearn hopes Selby will now defend his title in Wales early next year.
It is likely to be a mandatory defence against either Jonathan Barros or Eric Hunter, before a potential fight against European and Commonwealth featherweight champion Josh Warrington in Leeds in May or June 2016.
"I would love to see him come back to Wales now and have a big homecoming," said Hearn.
"He missed the atmosphere back home. It is very difficult when you're coming into an arena with not much atmosphere, to really start fast and get your heart racing.
"The Warrington fight is a really big fight, a huge fight next summer for the UK."
Hearn thinks Selby could be ready for a unification fight at the end of next summer.
"I think he has the ability to unify the division," said Hearn.
"What people saw tonight is that Lee is an outstanding fighter. Without doubt the unification fights are going to come.
"His career is going to continue to flourish and I think his reign as world champion is going to be a long one."