Melvin Jerusalem believes he wasn’t really at his best when he outclassed mandatory Mexican challenger Luis Castillo over the weekend.

“There’s still a lot of room for improvement,” Jerusalem said after posting a lopsided 12-round unanimous decision during Manny Pacquiao’s Blow-By-Blow at the Mandaluyong City College Gymnasium.

Though he didn’t say categorically that he wasn’t happy with his performance, Jerusalem feels there were still some things that he and his training team need to address.

“I still got hit (more than what I expected),” Jerusalem, who passed his first defense of the World Boxing Council minimumweight crown.

“I think we have to work on this so we don’t experience it next time I fight,” he added.

It appeared that Jerusalem was going to pull the plug on the erstwhile undefeated Castillo as early as the first round when he sent the Los Mochis native down with a perfectly-timed right to the chin.

Castillo got up at the count of six on unsteady legs and as soon as Japanese referee Yuki Fukuji ordered a resumption of action, Jerusalem pounced on the visibly dazed challenger.

A couple more rights landed but miraculously Castillo refused to hit the floor.

Then the bell rang and Castillo walked back to his worried cornermen all banged up and appearing like a skid row drunk.

“He is strong and very tough,” Jerusalem, 30, said.

He also admitted that Castillo succeeded in hurting him but he “didn’t show him that he got buzzed.”

So, what’s on the horizon for the Manolo Fortich, Bukidnon, native?

“I want to face the other champions in my division. Would love to face Oscar Collazo of Puerto Rico or Thammanoon Niyomtrong of Thailand.

Collazo, the World Boxing Organization ruler, stopped a jet-lagged and sleep-deprived Jerusalem in May last year in Southern California.

Niyomtrong, also known as Knockout CP Freshmart, is the World Boxing Association kingpin.

The International Boxing Federation supremo is also a Filipino—Pedro Taduran — making a matchup with him not possible at this time.

In the meantime, Jerusalem is to take a short break before going back to the gym.

While his next fight won’t happen until the first quarter of the coming year, Jerusalem is not taking any chances.

“A lot of fighters are after this WBC belt so I have to stay active even in training,” he added.