NEW YORK – Felix Trinidad Jr. said he always knew he was a middleweight.

He certainly proved that to a roaring crowd of more than 18,000 at Madison Square Garden, and to William Joppy, who tried to defend his title against the Puerto Rican hero.

	Felix Trinidad, right, knocked down William Joppy three times before earning the TKO in the fifth round.

Trinidad knocked Joppy down three times and stopped him at 2:25 of the fifth round early Sunday to take the WBA middleweight title.

He will now fight Bernard Hopkins, the IBF and WBC middleweight champion, at the Garden on Sept. 15.

"You guys saw tonight I'm a true middleweight. I beat the best middleweight tonight, and I will beat Hopkins," Trinidad said.

The former welterweight and junior middleweight champion demonstrated explosive power knocking down Joppy in the first, fourth and fifth rounds.

"He's a great champion," said the 30-year-old Joppy. "I never thought he could hit that hard. I never thought he would have the power that he had coming from 154 to 160 pounds. I've never been hit like that before."

Asked how he would deal with Trinidad's power, Hopkins sitting at ringside said: "Make it a street fight – elbows and knees."

Joppy opened the fight by jolting Trinidad with a right hand with just 15 seconds gone. But with 12 seconds left, Trinidad knocked Joppy down for a four count with a right-left-right combination to the head.

"I like knockouts. I look for knockouts. Thank God I got a knockout," said Trinidad, who boosted his record to 40-0 with his 33rd knockout.

The pro-Trinidad crowd was in a frenzy after the first round, and it never calmed down.

Joppy held his own with a left jab in the second round, but it became apparent that he simply could not get out of the way of Trinidad's right hand, even though it appeared he had the best of the third round.

Then, with 56 seconds gone in the fourth round, Trinidad landed a jarring right uppercut and moments later, he landed a right and a left hook that sent Joppy sprawling to the canvas. The defending champion from Silver Spring, Md., got up quickly and, by holding, running and ducking, managed to finish the round.

But his luck and his chin could not get him through the fifth.

The 28-year-old Trinidad, trained and managed by his father, hurt Joppy with a left-right combo 1:30 into the round. Then, 45 seconds later, a smashing left put Joppy down. He came up almost immediately and stumbled into a ring post. As Joppy reeled along the ropes, referee Arthur Mercante Jr. wrapped his arms around him and stopped the fight

As the Garden rocked, Trinidad threw his arms in the air in triumph, becoming the first former welterweight champion to win a middleweight title since another Latin star, Roberto Duran, did it in 1989.

Trinidad, who weighed in at 159¼ pounds, earned $10 million.

Joppy, 158¾, made $1.1 million for his second loss against 32 wins and a draw. He has 24 knockouts, but never came close to getting No. 25.