Rob de Castella, the marathon man from Down Under, took it to the top today. As runners from around the world disintegrated behind him like so many fizzled meteors and overheated cars, De Castella treated the feared Heartbreak Hill like a pitcher's mound and never broke stride.

Instead, the Australian broke the bank, conquering this 90th Boston Marathon in a course record 2 hours 7 minutes 51 seconds, the third fastest time in marathon history. Norway's Ingrid Kristiansen was the women's winner in 2:24:55, but was unable to achieve her goal of breaking her world record (2:21:06 in London last year).

"This was close to my best race," De Castella said, "especially when you consider I was in the lead from the start."

De Castella broke Alberto Salazar's course record by 57 seconds to win $60,000 (including $25,000 for the course record, $5,000 more for performance bonuses) and a new Mercedes-Benz. De Castella could have won an additional $50,000 if he had set a world record. This was the first year Boston gave out prize money, awarding the top 15 finishers for men and women.

De Castella already was shaking Gov. Mike Dukakis' right hand and wearing the victory wreath when Canada's Art Boileau (a personal-best 2:11:15) and Italy's Orlando Pizzolato (2:11:43) next reached the finish line. Bill Rodgers, the 38-year-old "Boston Billy," finished a surprising fourth at 2:13:36.

Boston's 26-mile 385-yard course did not relent so easily to Kristiansen, who aimed to break 2:20.

Kristiansen wore Nike's new yellow-and-black running "slippers" and at the 16-mile point, she was just 15 seconds off her record pace.

But Kristiansen, 30, said stomach cramps intervened at this point. Although her pace slowed over the second half of the course, she held on to win the $30,000 first prize (plus $5,000 in performance bonus for besting 2:26) and a Mercedes.

"Disappointing," she said. As Kristiansen's pace faded to slower than a six-minute mile over Heartbreak Hill near mile 21, one local TV reporter announced, "We're still looking for Joan Benoit-Samuelson, the local favorite."

Trouble was, Benoit-Samuelson is recovering from a foot injury and didn't even run today. Carla Beurskens of the Netherlands had closed within 500 meters of Kristiansen (about one minute behind) at the 16-mile point, "but I didn't have the speed to catch her."

Beurskens finished second at 2:27:35, a personal best by 15 seconds, and Lizanne Bussieres of Quebec finished third (2:32:16).

One world-best mark was set today: Canada's Andre Viger finished in 1:43:25 to win the men's wheelchair race and the $2,500 first-place prize. (John Hancock Financial Services, corporate sponsor of the event, decided to add $5,000 to Viger's prize for his record-setting performance, according to a spokesperson for the insurance company). Viger's mark was one minute better than the previous record.

At the start of the race, the temperature was 58 degrees with overcast skies, splendid for running. A gentle rain fell for several minutes in mid-race, then stopped and did not resume until all of the lead runners had finished.

The only men to have run a marathon faster than De Castella's wire-to-wire gem today are Portugal's Carlos Lopes (2:07:12) and Wales' Steve Jones (2:07:13), neither of whom ran today.

De Castella, 29, pointed out that both Jones (who served as a TV commentator here) and Lopes, the Olympic champion, have injured legs, so "in terms of runners who are in one piece, I'm No. 1."

This is the way the world looked to De Castella from Hopkinton to Copley Square today: Pete Pfitzinger, the Cornell MBA who won the U.S. Olympic trials two years ago, busted out in front with De Castella for the first five miles. Along the way, Pfitzinger must have blown a fuse, because he faded fast and didn't finish.

Meanwhile, Japan's Kunimitsu Ito, Boston's Greg Meyer (1983 Boston winner), and Kenya's Joseph Kipsang all stayed in a dense pack several yards behind De Castella. Meyer and Ito, who eats a prerace meal of rice cakes and honey, were overspent and dropped off by mile 15. Ito finished 10th (2:17:02) and Meyer finished 12th (2:17:29).

Kipsang's spirit and speed died in the hills of Newton. Like Pfitzinger, he was left for the roadside, a burnout victim. The only other real threat to De Castella was Arturo Barrios, a 23-year-old Mexican who set a world record at 10 kilometers (6.2 miles) in March. No one knew what to expect from Barrios today. Including Barrios.

At the 10-mile mark, Barrios was in 13th place. At the 15-mile mark, Barrios was fourth. All of Boston could see that Barrios was moving in a hurry. De Castella later said he didn't see Barrios the entire race. But, De Castella also said, "Someone told me at 15 miles that Barrios was in second, about 400 meters [one minute] behind me. I was a little concerned. I was preparing myself for a challenge."

De Castella had trained with Barrios once in the hills of Colorado. He was so impressed that he listed Barrios as his main competitor late last week.

Barrios came off Heartbreak Hill with legs wobbling. Welcome to the marathon. He held on for dear life as Boileau, Pizzolatto and finally Rodgers passed him. Barrios finished fifth, at 2:14:09, noble for a novice.

De Castella said that once Kipsang, the long-legged Kenyan, had faded in the hills, "I felt I was in control. After that, I was by myself. I became more concerned with the course."

De Castella had written checkpoint times on the back of his left hand before the race, to remind him the pace required to reach 2:08 and 2:10. He surpassed both marks. A fan approached him near mile 21 and De Castella pushed him away.

"I have a short temper," De Castella said. He also has a monstrous heart. He had finished a disappointing fifth in the 1984 Olympics and third in Chicago (a race won by Jones) last October, but said his confidence never wavered.

Pat Clohessy, De Castella's Australian coach since the runner was 14 years old, said of the marathoning troika of De Castella, Lopes and Jones, "I'm not about to claim that de Castella is better than the other two, but he's very consistent. And you have to realize he's only in the middle stage of his career. I don't think it's prudent to say who's better at this point."

A fire alarm sounded in the Copley Plaza Hotel during De Castella's press conference. The man who never lost his lead, showed he didn't lose his sense of humor today, either. Said he, "I hope we don't have to make a run for it."