As Iditarod defending champion Doug Swingley settled into White Mountain Monday night -- 77 miles from the Nome finish of the 28th Iditarod Trail Sled Dog Race -- his closest competitors steeled themselves and their dogs for the final grind in a different sort of contest.

Three top contenders driving within two hours of one another appeared to be launching a dash for second place.

Another four mushers, including the owners of nine previous Iditarod championships, were pushing down the Seward Peninsula in a battle for fifth.

Two mushers would be racing for eighth.

With a $525,000 total purse paid out to the top 30 places, the stakes in these secondary races often are as high as the prize once paid to race champions. Second place in the 2000 Iditarod, for instance, pays $52,500 -- some $15,000 more than fourth. A decade ago, second place paid only $35,000, and as recently as 1984 the champion earned only $24,000.

But as the annual 1,100-mile, Anchorage-to-Nome marathon entered its ninth night, one thing seemed certain.

If Swingley launches on schedule this morning after finishing a mandatory eight-hour rest and drives for Nome at the same pace that gave him victory last year, the 46-year-old could pass under the burled arch by late this morning, seizing his third championship in record time.

With mild temperatures and stiff-but-manageable breezes forecast for Nome region, only a freak accident -- sled shattering on a stump, dogs suddenly balking at the wind -- could loosen Swingley's lock on the championship, several top mushers said.

"Nobody is going to catch him with dog power," said five-time champ Rick Swenson at the Unalakleet checkpoint.

It would take a collision with a "meteor," is how three-time winner Jeff King put it.

But it was not for lack of trying.

Driving teams that posted travel times between checkpoints that often rivaled or beat Swingley's, nine other top racers were all moving in three distinct groups. As of Monday evening, they appeared locked in mini-races for positions that collectively paid nearly $300,000 in prize money.

"The race is heating up in the top 10," wrote 1989 champ Joe Runyan in a dispatch to the Internet.

Leading the pack was Kasilof musher Paul Gebhardt, who had been chasing Swingley all day, running about five hours behind the leader with 10 dogs.

After crossing the Norton Sound pack ice in five hours and 47 minutes -- 12 minutes faster than Swingley -- Gebhardt arrived at the village of Koyuk at the same moment Swingley pulled his snow hook to leave.

"Just as Swingley was hooking up his dogs for a departure at 6:52 a.m., a headlamp suddenly turned on and Gebhardt and team emerged from the dark of the bay," Runyan wrote. "Whoa, what a surprise. Doug had been spotted and identified. Gebhardt's dogs finally got a visual on the prey they have been chasing the last 24-hours."

Caught up in the moment, perhaps, Gebhardt loaded his sled and gave chase, spending only 10 minutes in Koyuk. But the illusion of close rivalry for first would be short-lived.

Swingley had rested more than five hours in Koyuk and was able to drive almost nonstop to White Mountain, a distance of 94 miles. He arrived at 5:33 p.m. after less than 11 hours.

But Gebhardt rested on the trail, taking nine hours and 42 minutes to reach Elim, about half the distance. He then began the 46-mile push to White Mountain only 45 minutes before Swingley arrived. Gebhardt was expected to arrive in White Mountain late Monday night.

Some 79 minutes after Gebhardt chased Swingley, Manley musher Charlie Boulding drove into Koyuk with seven dogs. Boulding, who had begun the race in last position and had earlier posted some of the fastest splits, had been slowing. His crossing of six hours and 31 minutes was a half hour slower than the two men ahead of him.

Boulding would remain in Koyuk nearly four hours. While he rested, Denali Park musher King drove off the ice, loaded his sled and drove out of the village in third position just after 10 a.m.

Like Gebhardt, King had crossed the Norton Bay ice slightly faster than Swingley. King would also rest on trail to Elim, arriving at 6:10 p.m., about an hour and a half behind Gebhardt. But King had made the run from Koyuk nearly two hours faster than Gebhardt.

As Buser and Swenson rested their teams in Koyuk, they talked about what might have been.

Buser said he was at a disadvantage this year because there wasn't enough snow early in the season to do much long-distance training and put in a lot of 25-mile runs. Swingley, on the other hand, had been practicing with 150-mile runs.

Swingley's strong showing has proven the value of distance training, Buser said.

Swenson said an accident just outside the Rohn checkpoint that injured one of his dogs set him back by a couple of hours. If not for that, said Swenson, "I would have given Doug a run for his money."

+ Mary Pemberton of the Associated Press contributed to this story.