South Korea's Park Chong-pal knocked out Indonesian challenger Polly Pesireron in the fifth round Tuesday in his first defense of his World Boxing Association super middleweight title.

SEOUL, South Korea (AP) _ After a slow start, Park became the aggressor in the third round, controlling the Indonesian challenger with a combination of left hooks and body punches.

Pesireron, 31, responded with powerful hooks but failed to slow the fast- moving champion. In the fifth round, Park caught Pesireron against the ropes and unleashed a devastating attack. The challenger collapsed with 35 seconds left in the round after two blows to his left trunk.

''Pesireron's punch was powerful, but he was too slow,'' Park said later in a nationally televised interview in Chonju, about 125 miles south of Seoul. ''I'm ready to fight any boxers, including Obelmejias and Hearns.'' The 28-year-old Park, who won the title in December from Mexico's Jesus Gallardo, is scheduled to make a mandatory title defense against Fulcencio Obelmejias of Venezuela in May. In 1981, Obelmejias registered an eighth-round knockout of Park.

He is also seeking a bout with WBC middleweight champion Thomas Hearns, a matchup his handlers have said American promoter Bob Arum was also interested in.

Hearns, the only man ever to hold at least a piece of four different world titles, would be seeking a fifth if the bout came off.

''I've been training enough to catch anyone,'' Park said. ''After developing more techniques, such as body blows, that were effective today, I think I can beat Hearns, too, even though many people believe he will win.''

Park, who fought at 167 1/2 pounds, improved to 46 wins, including 38 knockouts, three losses, one draw and one no decision. Pesireron, 168, suffered his fourth defeat against 14 victories and one draw.