LONDON -- One 3-pointer after another, Kevin Durant shot down Argentina -- and perhaps the notion that defense wins championships.

This U.S. men's Olympic basketball team is living proof that the best defense is a good offense. The road to gold in London is built on scores, not stops.

Durant scored 17 of his 28 points during the Americans' 42-point third quarter, turning a one-point game into a blowout that sent the U.S. soaring into the quarterfinals with a 126-97 victory on Monday night.

Two nights after surviving their first real test in a 99-94 victory over Lithuania, the Americans seemed headed for another tight finish. Argentina shot 56 percent in the first half and the U.S. led just 60-59.

Minutes later, the game -- the last before single-elimination play starts -- was effectively over.

"I think we did a great job of responding from last game," Durant said. "It was a tough game and so was the first half tonight. Guys played together. That second half is how we want to play."

The NBA scoring champion matched the Argentines' point total in the period, going 5-of-6 from 3-point range, the last one from well beyond 25 feet. The Americans didn't stop shooting and scoring until Carmelo Anthony made a 3-pointer in the final second of the quarter while taking what he and the U.S. bench right behind him felt was a cheap shot from Argentina's Facundo Campazzo, setting off an exchange of words and technical fouls.

It was too late by then for the Argentines. They needed to get closer to the U.S. shooters much sooner, and that was hard to do from some of the spots where Durant was pulling up.

The Americans (5-0) will play Australia (3-2) in a quarterfinal game Wednesday.

LeBron James added 18 points, including the Americans' first seven of the third quarter before Durant took over. Chris Paul finished with 17.

"We're great shooting team, but in close games sometimes you've got to go down and get some easy ones, and I wanted the ball, whether it was layups or in the post," James said. "Once you get a couple easy ones at the rim, then the 3-pointers open up and you saw what KD was able to do."

Durant's 3-pointer after James' surge gave the U.S. 10 points in 2:10 of the second half, and he made back-to-back 3s midway through the period to make it 85-68. Then he nailed consecutive 3s again later in the quarter, one from beyond the hash line, a distance that most players would never consider pulling up from.

"I really didn't pay attention to where the line was," Durant said. "When I caught that ball I was going to shoot it."

With his 17 points, Durant tied Argentina all by himself in the third quarter. He finished 8 of 10 from 3-point range, where the U.S. team was 20 of 39.

Durant, who holds the U.S. scoring record with 38 points in the 2010 world championship, might have threatened that if not for the lopsided score. He checked out for good about a minute into the fourth quarter.

"It sort of developed, but anybody in their right mind, when he gets shooting the ball like that, there's only one thing to do: Get the ball to him," Paul said of the plan to feed Durant. "Luckily, we have a team that has the presence of mind to get it to him. He is unbelievable. We have to yell at him to shoot the ball and as you see, he usually makes it."

Manu Ginobili scored 16 points for Argentina (3-2), which would have won Group A via tiebreaker if it had blown out the U.S. Instead, it finished third and will face Brazil in the quarterfinals.

"In the second half the U.S. really upped the ante, started playing very hard. They had a lot of defensive attacks and they started to run a lot more," Argentina's Leonardo Gutierrez said through a translator. "They also had an incredibly high percentage of 3-pointers. In the third quarter, they had three or four 3-pointers. They got one after another, all in a row, and we had a strong offense and gained many points. but that is something very difficult for any team to overcome."

A crowd featuring former Secretary of State Condoleezza Rice and ex-heavyweight boxing champion Evander Holyfield was treated to an offensive show in the first half with little more defense than the NBA All-Star game. A basket on one end was answered quickly by a shot on the other in what was shaping up as a thriller between the last two Olympic champions.

But the U.S. simply has too much offense, even if the defense could use some tightening up.

The Americans have two days to work on it before facing the Australians (3-2), who pulled a surprise earlier Monday, handing Group B champion Russia its first loss, 82-80, on Patty Mills' 3-pointer as time expired.

Then again, maybe the defense is fine as it is.

James, who scored nine of his 20 points in the final four minutes Saturday, now has 225 points as a U.S. Olympian, just six away from Charles Barkley for third place on the U.S. career list.

The closer on Saturday, James was a late arrival Monday, returning from the locker room area, leaping over a barrier like an Olympic hurdler to jump back in line in time for the national anthem.

Still missing at the start was the U.S. defense.

The Americans, who insist their defense is their strength, allowed Argentina to make 11 of its first 15 shots, falling behind 30-29 when Gutierrez made a 3-pointer with 1:03 left in the first quarter. Durant's 3-pointer as time expired gave the U.S. a 34-32 lead headed to the second.

The U.S. could lead by no more than six in the second -- though nobody was quite sure when that happened. Andre Iguodala's ferocious dunk on the fast break was thrown down with such force that it hit his chest and ricocheted back up through the basket so quickly that it was unclear if it went in at all. The public address announcer and scoreboard operator counted it, but Argentina simply pushed the ball up the other way without inbounding as if the shot had missed. Replays showed it clearly went all the way down, making it 45-39.

The game between the longtime rivals got testy in the second half, and they could see each other again soon. They would meet in the semifinals for the third straight Olympics if both win Wednesday.

"You kind of want to send a message a little bit," Kobe Bryant said. "This was the second game in a row that a team has played us close. We didn't want to give them confidence."

The teams played a physical exhibition game last month in Barcelona, the Argentines trimming a 20-point deficit to four in the final minutes before losing 86-80.

Campazzo, starting because Knicks-bound veteran point guard Pablo Prigioni is out with kidney stones, said he apologized to Bryant but not to Anthony, saying Paul didn't apologize for hitting him.

"He told me it's not necessary, and I told him I was really sorry," Campazzo said. "But before Chris Paul punched me. It's part of the game."