MANILA, Philippines?The punches landed as promised.

World flyweight champion Nonito Donaire Jr. Sunday knocked down Mexican challenger Raul Martinez four times to keep his IBO/IBF titles by technical knockout in the fourth round at the Araneta Coliseum in Quezon City.

And former World Boxing Council champion Brian ?The Hawaiian Punch? Viloria was just as impressive, knocking out Mexican Ulises Solis with a crushing right to the jaw in the 11th round to wrest the IBF light flyweight crown.

The sensational victories before a huge crowd at the Big Dome thrilled a nation that is hoping for, if not anticipating, a similar outcome when its top boxing star, Manny Pacquiao, faces Briton Ricky Hatton on May 2 in Las Vegas.

Donaire?s and Viloria?s triumphs crowned an explosive morning for Filipino boxers, who scored four knockouts against foreign opponents. In the undercard, Iloilo?s Denver Cuello stopped Hiroshi Matsumoto of Japan in four rounds to capture the WBC international minimum weight title, while super flyweight Drian Francisco battered his Indonesian foe into submission in two.

True to his moniker ?The Filipino Flash,? Donaire made it quick, finishing off the erstwhile unbeaten ?Cobrita? Martinez at the 2:42 mark of the fourth round with a left uppercut that sent his rival down a fourth time.

Martinez, floored twice in the first round and once in the second, immediately got up, but referee Pete Podgorski had seen enough and stopped the bout.

?I just did what I had to do,? said the 27-year-old Donaire, who improved his record to 21-1. ?I was jittery and nervous, especially when they called my name.?

Executioner no more

Donaire, who was defending his International Boxing Federation and International Boxing Organization titles, said he was also under pressure to match Viloria?s crackling performance a bout earlier.

Viloria became a champion again in the 108-lb class by dethroning Solis with the kind of punch that made him a WBC titlist in September 2005.

Throwing combinations, the Hawaii-raised son of Ilocanos bloodied Solis under the right eyebrow in the fifth and on the left eyelid in the seventh before putting him away with four seconds to go in the 11th.

The powerful blow sent the champion, also known as a Filipino executioner, head first to the canvas. Solis managed to get back to a sitting position but made no effort to rise as referee Bruce McTavish counted him out.

As supporters hoisted the teary-eyed Viloria, Solis fell back to the canvas, staying there for a while before he was carried to his corner, where he was fully revived.

?He?s a Filipino executioner no more. It ended today,? Viloria, 28, said of Solis, who was defending the title for the ninth time and counted Filipinos Rodel Mayol, Bert Batawang and Donaire?s elder brother Glenn among his victims.

Tough fight, great fighter

Viloria, who won his first title with a first-round knockout of Eric Ortiz, improved to 25-2 while Solis dropped to 28-2-2.

?I got a great right hand,? Viloria said later. ?I admit I haven?t been using it in my past fights. I knew that if I toyed with him with my right hand, he?s going to come down.?

?I fought a great fighter,? said Solis, who later asked for a rematch. ?It was a tough fight. But a great champion like me comes back.?

Top Rank?s Bob Arum, who collaborated with Solar Sports in presenting the card dubbed ?The Flash and the Furious,? said he planned to move Donaire to the super flyweight (115 lb) class with American Eric Morel as a possible opponent.

For Viloria, Arum said he was already thinking of pitting him against Puerto Rico?s Ivan Calderon, who is in the top 10 list of best pound-for-pound boxers in the world.

Swollen fist

Donaire, who was born in Bohol and grew up in General Santos City before leaving for the United States at 11, said he would wait for his left hand to heal before taking another fight.

He showed the media the swollen left fist which inflicted on Martinez his first loss in 25 fights.

The Texas-based Martinez, whom Donaire also defeated when they squared off in the US Olympic trials in 2000 during their amateur days, tried to argue with the referee after hitting the deck a fourth time.

But Donaire was already jumping up and down the ring with hands raised to celebrate his third successful defense of the title he wrested with a sensational knockout of famous Armenian-born Australian Vic Darchinyan two years ago.

Father-son breakup

Martinez gamely stood up and embraced Donaire, then amused the crowd when he ran around the ring carrying the Philippine flag.

?I love this country. You are a beautiful, gentle people. I came here to win by knockout, to take the crown, but unfortunately I lost,? Martinez later said. ?I don?t think there?s anything I could have done.?

With welts all over his face and a bruised right eyebrow, Martinez said: ?Donaire is a real champ. Real fast. I keep throwing punches but he gives a left. Then he throws a right.?

Donaire pulled off his most impressive title defense minus his estranged father and former trainer Nonito Sr., who didn?t show up although the son had sent him tickets.

The father-son breakup began when Nonito Jr.?s wife, former RP taekwondo-jin Rachel, took over as his manager last year and hired former world champion Dodie Boy Peñalosa as his trainer.

Victorious Cuello, Francisco

The twin title fights were preceded by Cuello?s auspicious KO victory over Matsumoto.

In the other bouts, light flyweight Sonny Boy Jaro (30-7-5, 19 KOs) needed just 74 seconds to put away Eriberto ?Yukka? Gejon (25-5-1, 14 KOs) in a 10-round special attraction.

Francisco (16-0-1, 12 KOs) floored Indonesia?s Sahril Fabanyo (2-2-1) with a left hook to the body in 1:30 of the second round to win their 12-round super flyweight bout.